Truck Insurance Exchange v. Kaiser Cement CA2/4 ( 2022 )


Menu:
  • Filed 1/7/22 Truck Insurance Exchange v. Kaiser Cement CA2/4
    NOT TO BE PUBLISHED IN THE OFFICIAL REPORTS
    California Rules of Court, rule 8.1115(a), prohibits courts and parties from citing or relying on opinions not
    certified for publication or ordered published, except as specified by rule 8.1115(b). This opinion has not been
    certified for publication or ordered published for purposes of rule 8.1115.
    IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA
    SECOND APPELLATE DISTRICT
    DIVISION FOUR
    TRUCK INSURANCE EXCHANGE,                                                      B278091
    Plaintiff and Appellant,
    (Los Angeles County
    v.                                                                    Super. Ct. No.
    BC249550)
    KAISER CEMENT et al.,
    Defendants, Cross-complainants
    and Appellants;
    LONDON MARKET INSURERS,
    Defendant and Appellant.
    INSURANCE COMPANY OF THE
    STATE OF PENNSYLVANIA,
    Cross-Defendant and Appellant.
    GRANITE STATE INSURANCE
    COMPANY, et al.,
    Defendants and Respondents.
    APPEAL from a judgment of the Superior Court of
    California, Kenneth R. Freeman, Judge. Affirmed in part and
    reversed in part.
    The Cook Law Firm, Philip E. Cook and Brian J. Wright, for
    Defendant and Appellant, Kaiser Cement and Gypsum
    Corporation.
    Pia Anderson Moss Hoyt, Scott R. Hoyt, Adam L. Hoyt,
    Greines, Martin, Stein & Richland, Robert A. Olson and Jonathan
    H. Eisenman, for Plaintiff, Appellant, and Respondent Truck
    Insurance Exchange.
    Duane Morris, Brian A. Kelly, Paul J. Killion and Kathryn
    T.K. Schultz, for Defendants, Respondents and Appellants London
    Market Insurers.
    Lynberg & Watkins and Wendy E. Schultz for Cross-
    Defendant, Respondent and Appellant the Insurance Company of
    the State of Pennsylvania and Defendant and Respondent Granite
    State Insurance Company.
    Squire Patton Boggs, David Godwin and Tania L. Rice for
    Cross-Defendant and Respondent Continental Insurance.
    Company (for itself and its successor to certain policies issued by
    London Guarantee & Accident Company of New York).
    Selman Breitman, Elizabeth M. Brockman and Calvin S.
    Whang for Defendants and Respondents National Casualty
    Company and Sentry Insurance a Mutual Company, as
    assumptive reinsurer of Great Southwest Fire.
    Crowell & Moring, Mark D. Plevin and Christine E.
    Cwiertny for Defendants and Respondents Fireman’s Fund
    Insurance Company and Allianz Underwriters Insurance
    Company f/k/a Allianz Underwriters.
    Kendall Brill & Kelly, Alan Jay Weil; Shipman & Goodwin,
    James P. Ruggeri, Katherine M. Hance and Edward B. Parks II for
    Defendant and Respondent First State Insurance Company.
    2
    Aiwasian & Associates and Deborah A. Aiwasian for
    Defendant and Respondent Westchester Fire Insurance Company.
    Davis Wright Tremaine, Everett W. Jack, Jr. Lawrence B.
    Burke for Defendant and Respondent Transport Insurance
    Company, successor in interest to Transport Indemnity Company.
    Traub Lieberman Straus & Shrewsberry, Kevin P.
    McNamara for Defendant and Respondent Evanston Insurance
    Company as successor by merger with Associated International
    Insurance Company and TIG Insurance Company (formerly known
    as Transamerica Insurance Company and as successor by merger
    to International Insurance Company).
    __________________
    INTRODUCTION
    This is the latest of several opinions issued by this court in
    litigation concerning comprehensive general liability (CGL)
    insurance coverage for asbestos bodily injury claims (referred to by
    the parties as ABIC) against Kaiser Cement and Gypsum
    Corporation (Kaiser). The ABIC were brought mostly by laborers
    who became ill and/or died from exposure to asbestos-containing
    products manufactured by Kaiser over more than 30 years.
    Truck Insurance Exchange (Truck), Kaiser’s primary
    insurer, commenced this action in 2001, after making more than
    $50 million in indemnity payments to resolve ABIC against Kaiser.
    Truck sought declaratory relief that its primary coverage of ABIC
    had been exhausted and it had no further duty to defend or
    indemnify Kaiser. Truck also sought contribution from certain of
    Kaiser’s excess insurers. Kaiser cross-claimed against Truck and
    Kaiser’s excess insurers, seeking a declaration of coverage.
    3
    A.    Earlier Opinions
    In the first opinion, London Market Insurers v. Superior
    Court (2007) 
    146 Cal.App.4th 648
     (LMI), a different panel of this
    court resolved what it described as a matter of first impression in
    California: the meaning of “occurrence” in CGL policies as it relates
    to per occurrence limits of liability and deductibles in the context of
    ABIC. (Id. at p. 651.) LMI held that for purposes of per occurrence
    limits and deductibles, an “occurrence” under Truck’s CGL policies
    is each claimant’s “injurious exposure to [Kaiser’s] asbestos
    products,” not (as Truck had contended) Kaiser’s manufacture and
    distribution of those products. (Id. at pp. 652, 672.)
    On June 3, 2011, this court issued a second opinion: Kaiser
    Cement & Gypsum Corp. v. Insurance Co. of the State of
    Pennsylvania (2011) 
    196 Cal.App.4th 140
    . After granting review,
    the Supreme Court transferred the case back to this court with
    directions to vacate the decision and reconsider it in light of State
    of California v. Continental Ins. Co. (2012) 
    55 Cal.4th 186
    (Continental Insurance).
    Having done so, this court issued a third opinion, Kaiser
    Cement and Gypsum Corp. v. Insurance Co. of the State
    Pennsylvania (Apr. 8, 2013) B222310, opn. ordered nonpub. Jul. 17,
    2013 (ICSOP)).1 As discussed further below, that opinion decided
    issues relating to obligations of the Insurance Company of the
    State of Pennsylvania (ICSOP) under an excess insurance policy it
    had issued to Kaiser. (Id. at pp. 16–36.)
    1    While ICSOP is unpublished, it is citable as law of the case
    under California Rules of Court, rule 8.1115(b)(1).
    4
    B.    The Present Dispute
    This opinion resolves an appeal and a cross-appeal from a
    judgment entered following a three-phase bench trial involving
    Kaiser, Truck, and certain of Kaiser’s excess insurers: ICSOP,
    London Market Insurers,2 Granite State Insurance Company,
    Continental Insurance Company, National Casualty Company,
    Sentry Insurance, Fireman’s Fund Insurance Company, Allianz
    Underwriters Insurance Company, First State Insurance
    Company, Westchester Fire Insurance Company, Transport
    Insurance Company, Evanston Insurance Company, and TIG
    Insurance Company. The trial commenced in 2014 on Truck’s
    Fourth Amended Complaint and Kaiser’s Third Amended Cross-
    Complaint. The Honorable Kenneth R. Freeman presided over all
    three phases.
    1.    Phase I
    Phase I addressed whether Truck’s claim to recover certain
    per occurrence deductibles from Kaiser for ABIC was barred by the
    applicable statute of limitations. Truck provided primary insurance
    coverage to Kaiser over 19 annual policy periods. Kaiser was and
    continues to be subject to ABIC arising from exposure to its
    asbestos-containing products during some or all those 19 years.3
    2    London Market Insurers refers to Certain Underwriters at
    Lloyd’s of London and Certain London Market Insurance
    Companies.
    3     ABIC are “long-tail” claims alleging “a series of indivisible
    injuries attributable to continuing events . . . . [that] produce
    progressive damage that takes place slowly over years or even
    5
    While most CGL policies have per occurrence deductibles, per-
    occurrence limits, and aggregate limits of liability, during a nine-
    year period from 1971 to 1980, Truck’s primary policies had no
    aggregate limits.
    A dispute arose between the parties about Kaiser’s obligation
    to pay deductibles because, before LMI, the meaning of
    “occurrence” under the primary policies as it related to per
    occurrence deductibles for ABIC was uncertain. The parties
    therefore operated under a “billing convention” (Convention)
    whereby Truck charged a single deductible for each policy year
    regardless of the number of individual claims instead of charging a
    per claim deductible. The parties each unilaterally reserved the
    right to challenge the Convention through various correspondence
    exchanged over the years.4
    In January 2007, after this court in LMI defined “occurrence”
    as the separate injurious exposure of each individual claimant,
    Truck reimbursed Kaiser for defense and indemnity costs. Kaiser
    incurred those costs because of Truck’s previous incorrect
    interpretation of “occurrence.” But Kaiser argues Truck improperly
    withheld approximately $9.5 million in per occurrence deductible
    charges from the reimbursement. In August 2007, Truck filed a
    second amended complaint seeking to recover the disputed per-
    occurrence deductible payments from Kaiser for the period the
    Convention was in effect. In defense, Kaiser argued the four-year
    statute of limitations applicable to contract actions barred any
    decades. Traditional CGL insurance policies . . . are typically
    silent as to this type of injury. [Citation.]” (Continental
    Insurance, supra, 55 Cal.4th at pp. 195–196.)
    4      For example, in June 1991 correspondence to Truck, Kaiser
    asserted it “reserve[d] its right to . . . challenge the [C]onvention.”
    6
    claim for deductibles arising before 2003 (four years prior to
    Truck’s second amended complaint). Kaiser cross-complained to
    receive what it contended it was entitled to under Truck’s
    insurance policies, including the withheld deductible payments.
    The trial court opined “that the issues presented in Phase I
    present a very close call.” Ultimately, it held Truck’s claim for
    additional deductibles did not accrue until this court clarified the
    definition of occurrence in the 2007 LMI decision. It also concluded
    the parties’ Convention “essentially operated as a tolling
    agreement,” allowing Truck to pursue collection of deductibles for
    claims resolved before 2003. The trial court certified its ruling for
    review pursuant to Code of Civil Procedure section 166.1, stating it
    presented “controlling questions of law as to which there are
    substantial grounds for difference of opinion.” The Phase I decision
    was incorporated into the final judgment. Kaiser appeals.
    We agree with the trial court that the Phase I issues present
    a close call. With the benefit of additional time and substantial
    additional briefing, however, we have come to different conclusions
    on the merits. Truck’s right to collect a deductible accrued each
    time it paid a settlement or judgment on each claim, including
    claim payments made before LMI. Moreover, we see no evidence
    that the parties intended the Convention to “operate[ ] as a tolling
    agreement.” Because any purported waiver of a statute of
    limitations defense must be in writing pursuant to Code of Civil
    Procedure section 360.5, and no such writing exists, Kaiser did not
    waive the statute of limitations. Thus, we conclude the statute of
    limitations bars Truck from recovering from Kaiser (or using as a
    set-off against amounts it owes Kaiser) any unpaid deductible
    payments for claims where Truck made any indemnity payment
    7
    more than four years before Truck filed its second amended
    complaint.
    Accordingly, we reverse the portion of the judgment relating
    to the Phase I decision and remand for further proceedings
    consistent with this opinion.
    2.    Phase II
    Phase II addressed whether Truck could apportion losses
    against all its policies, not just against Truck’s no-aggregate limit
    1974 policy that Kaiser selected pursuant to Armstrong World
    Industries Inc. v. Aetna Casualty & Surety Co. (1996) 
    45 Cal.App.4th 1
     (Armstrong).
    We begin with a brief summary of Armstrong, supra, and
    related cases, in order to frame the issue addressed in Phase II.
    Armstrong holds that once a policy is triggered, the policy
    typically obligates the insurer to pay “all sums” that the insured
    shall become liable to pay as damages. (Armstrong, supra, 45
    Cal.App.4th at p. 105.) With long-tail injuries such as ABIC, this
    may include damages attributable to other policy periods. (Ibid.)
    The term “trigger” is used to describe the operative event
    that must happen during the policy period to activate the
    insurer’s defense and indemnity obligations. (Montrose Chemical
    Corp. v. Admiral Ins. Co. (1995) 
    10 Cal.4th 645
    , 655, fn. 2
    (Montrose I); Continental Insurance, supra, 55 Cal.4th at p. 196.)
    A trigger may be (1) “a single event resulting in immediate
    injury[;]” (2) “a single event resulting in delayed or progressively
    deteriorating injury[;]” or (3) a continuing event resulting in
    single or multiple injuries over time. (Montrose I, 
    supra,
     10
    Cal.4th at p. 666.)
    The trigger determines which policy or policies may provide
    coverage. (Stonelight Tile, Inc. v. California Ins. Guarantee Assn.
    8
    (2007) 
    150 Cal.App.4th 19
    , 35 (Stonelight Tile).) Where damages
    continue throughout successive policy periods, as with ABIC, all
    insurance policies in effect during those periods are triggered.
    (Montrose I, 
    supra,
     10 Cal.4th at p. 677, fn. 17.) Coverage is not
    limited to the policy in effect at the time of the precipitating
    event or condition. (Ibid.) Thus, the insurer on a triggered policy
    may be liable (up to its policy limit) for the entirety of the
    ensuing damage or injury, not just the injury or damage
    occurring during that policy period. (Continental Insurance,
    supra, 55 Cal.4th at pp. 199–200; Aerojet-General Corp. v.
    Transport Indemnity Co. (1997) 
    17 Cal.4th 38
    , 56-57 (Aerojet);
    Armstrong, supra, 45 Cal.App.4th at p. 105.)
    As a result, where a continuous loss is covered by multiple
    policies, the insured may elect to seek indemnity under a single
    policy with adequate policy limits. (Montrose I, supra, 10 Cal.4th
    at p. 664.) If that policy covers “all sums” for which the insured is
    liable, as most CGL policies do, that insurer may be held liable
    for the entire loss. (Id. at p. 665; Armstrong, supra, 45
    Cal.App.4th at pp. 49–50.) “The insurer called upon to pay the
    loss may seek contribution from the other insurers on the risk.
    [Citation.]” (Stonelight Tile, supra, 150 Cal.App.4th at p. 37.)
    Kaiser selected Truck’s 1974 primary policy, which has no
    aggregate limit of liability, to respond to all ABIC, obligating
    Truck to pay “all sums” for which Kaiser was liable. The parties
    have stipulated that the “continuous trigger” and “all sums”
    approach, as applied in Aerojet, supra, 
    17 Cal.4th 38
    , and
    Armstrong, supra, 
    45 Cal.App.4th 1
    , govern and support Kaiser’s
    selection of the Truck 1974 policy, when triggered, to respond to
    ABIC.
    9
    This brings us to the Phase II issue, which relates to
    Truck’s effort to apportion liability to policies other than its 1974
    no-aggregate limit policy. In ICSOP, this court held that all of
    Kaiser’s primary policies must horizontally exhaust before ICSOP’s
    excess policies attached. (ICSOP, supra, at p. 34.) After ICSOP,
    and in spite of Kaiser’s Armstrong election of the 1974 policy,
    Truck sought to exhaust other primary policies in other years by
    apportioning claims triggering the 1974 policy across other
    primary policies it had issued to Kaiser. Unlike the 1974 policy,
    those other policies did contain aggregate limits. The trial court
    rejected Truck’s apportionment scheme, finding it would erode
    Kaiser’s coverage for asbestos claims available under Truck’s
    aggregate-limit policies and the excess policies above them.
    Truck appeals the trial court’s Phase II decision. We affirm.
    3.    Phase III-A
    The Phase III-A trial5 dealt with two issues. The trial court
    first addressed whether horizontal or vertical exhaustion applied to
    Truck’s claims against the excess insurers. Because Truck was a
    primary insurer whose policies had not exhausted, the trial court
    rejected Truck’s argument that the excess insurers had an
    obligation to “dropdown” and into Truck’s shoes as a primary
    insurer. Truck appeals, based on the recent California Supreme
    Court decision in Montrose Chemical Corp. of California v.
    Superior Court (2020) 
    9 Cal.5th 215
     (Montrose III). Montrose III
    held that vertical exhaustion applied to multiple layers of excess
    insurance, but did not address exhaustion of primary insurance.
    The second Phase III-A issue considered whether Truck’s
    $5,000 per occurrence deductible operated to reduce Truck’s per
    5     There was no Phase III-B trial.
    10
    occurrence indemnity obligation under the 1974 policy from
    $500,000 to $495,000, with Kaiser being responsible for a $5,000
    per occurrence deductible, or—as the excess insurers contend—
    Truck had to pay $500,000 in addition to the $5,000 deductible
    paid by Kaiser. The trial court found that per the policy language,
    the $5,000 deductible operated to reduce Truck’s indemnity
    obligation to $495,000. Excess insurers LMI and ICSOP
    cross- appeal the second issue.
    We affirm on both Phase III-A issues.
    PHASE I: STATUTE OF LIMITATIONS
    As noted above, Phase I addressed a statute of limitations
    issue. The parties adopted the Convention to address their
    uncertainty over the meaning of an “occurrence” under the policies,
    as it relates to per-occurrence limits and deductibles. When LMI
    resolved the question, the issue of accrual of claims for deductibles
    came to the fore. The trial court concluded the parties’ unilateral
    reservations of rights to challenge the Convention tolled the
    running of the statute of limitations, presumably meaning Truck
    could recover unpaid deductibles for all past claims. Kaiser
    challenges this result, arguing Truck’s claim for unpaid deductibles
    accrued when each claim was paid, and the statute was not tolled.
    This would mean that any claim for deductibles relating to claims
    where Truck made an indemnity payment more than four years
    before Truck filed its second amended complaint in August 2007
    was untimely and barred by the statute of limitations. We agree
    with Kaiser and reverse and remand to the trial court for further
    proceedings consistent with this opinion.
    11
    A.    FACTUAL BACKGROUND
    1.    Stipulated Facts
    In the trial court, Kaiser and Truck stipulated to the
    following facts relating to Phases I and II:
    a. Common Facts
    Kaiser Cement and Gypsum Corporation (“Kaiser Cement”)
    and its subsidiary Kaiser Gypsum Company (“Kaiser Gypsum,”
    and with Kaiser Cement, “Kaiser’’) have been the subject of
    thousands of ABIC alleging exposure to asbestos-containing
    products manufactured by Kaiser Cement or Kaiser Gypsum.
    Kaiser was issued primary insurance coverage, covering
    the period from 1947 to 1987, by four different insurance
    companies.6
    6     Three other insurance carriers issued primary insurance
    policies to Kaiser, but their policy limits have been exhausted.
    These policies were not at issue in Phase I. Fireman’s Fund
    Insurance Company (“Fireman’s Fund”) issued primary
    insurance policies to Kaiser covering the period from January 1,
    1947 through December 31, 1964. Fireman’s Fund’s aggregate
    policy limits have been paid, exhausting all of the limits of
    Fireman’s Fund primary coverage that apply to ABIC as of April
    30, 2004. Home Indemnity Company (“Home”) issued primary
    insurance policies to Kaiser covering the period from April 1,
    1983 through April 1, 1985. Home’s aggregate policy limits of $2
    million have been paid, exhausting all of the limits of Home
    primary coverage that apply to ABIC as of December 14, 1999.
    National Union Fire Insurance Company of Pittsburgh, PA
    (“National Union”) issued primary insurance policies to Kaiser
    covering the period from April 1, 1985 through April 1, 1987.
    National Union’s aggregate policy limits of $2 million have been
    12
    Truck issued primary CGL policies to Kaiser covering the
    period from December 31, 1964 through April l, 1983. Truck’s
    policies provide coverage for bodily injury and property damage
    up to per occurrence limits of liability. For many—but not all— of
    the policy years, the policies also contain an annual aggregate
    limit for product liability claims:
    a. Truck’s policies in effect from December 31, 1964 to
    January 30, 1971 have a $100,000.00 per person, a
    $300,000.00 per occurrence, and a $300,000.00 annual
    aggregate limit for all bodily injury products liability
    claims.
    b. Truck’s policies in effect from January 30, 1971 to April
    1, 1980 have per occurrence limits of $500,000.00 for
    bodily injury with no annual or other aggregate limits
    for products liability claims.
    c. Truck’s policies in effect from April 1, 1980 to April 1,
    1983 have per occurrence limits of $500,000.00 for bodily
    injury and $1,500,000.00 annual aggregate limits for
    products liability claims.
    Each of the policies required Kaiser to assume a portion of
    the losses in the form of deductibles and loss adjustment
    expenses.
    The policies defined “occurrence” as “an event, or
    continuous or repeated exposure to conditions which results in
    personal injury or property damage during the policy period. All
    such exposure to substantially the same general conditions
    existing at or emanating from each premises location shall be
    deemed one occurrence.”
    paid, exhausting all of the limits of National Union primary
    coverage that apply to ABIC as of August 31, 2000.
    13
    Beginning in the late 1970s, Kaiser tendered ABIC, along
    with a number of early asbestos property damage claims, to
    Truck, which began defending against such claims and
    indemnifying Kaiser.
    Kaiser’s other primary insurers, Fireman’s Fund, Home,
    and National Union, refused to participate. In February 1990,
    Kaiser and Truck filed suit against Fireman’s Fund, Home, and
    National Union. Kaiser entered into three separate settlement
    agreements with the other primary insurers in 1992 and 1993.
    Under those settlement agreements, Truck continued
    handling the defense of Kaiser’s ABIC while each of the other
    three primary insurers contributed to both defense and
    indemnity for ABIC according to specific formulas set forth in the
    settlement agreements.
    As a result of the exhaustion of the Fireman’s Fund, Home,
    and National Union primary policy limits, Truck has been the
    only remaining primary insurer responding to ABIC as of April
    30, 2004.
    On April 30, 2001, Truck filed its initial complaint in this
    action, alleging its policy limits for ABIC were exhausted, and
    seeking a judicial declaration that Truck had no further
    obligation to defend or indemnify Kaiser for ABIC.
    In 1981, Truck made the following assumptions regarding
    application of its policies to the ABIC filed against Kaiser:
    (a) California would adopt the “exposure theory” for triggering
    insurance coverage; and (b) all ABIC against Kaiser would be
    considered as arising out of one occurrence.
    Prior to 1987, Truck had set up one claim file for each
    policy year. Truck did not allocate indemnity and expenses for
    any individual asbestos claimant to more than one policy year but
    14
    instead allocated payments to policy years by using a single date
    of loss to place the claimant within a single, specific policy year.
    Beginning in approximately 1987, Truck established the
    Convention, under which it set up a master asbestos claim file for
    each policy year that broke down each indemnity payment and
    expense item (per claimant) into the number of years of exposure
    to Kaiser’s product(s) and prorated it into each policy year.
    Kaiser agreed to this allocation method for deductible
    billing purposes, as it was beneficial to Kaiser, but Kaiser
    reserved its rights to challenge Truck’s allocation of indemnity
    payments later.
    During this coverage action, which began in 2001, Kaiser
    has taken different positions on the number of occurrences giving
    rise to ABIC, including its allegations that ABIC arise from a
    single occurrence, and that ABIC arise from a small number of
    occurrences.
    Until the January 2007 LMI decision, Truck and Kaiser
    both believed the number of occurrences arising from ABIC and
    Kaiser’s per occurrence deductible obligation as called for under
    the Truck policies were unresolved questions of law that a court
    would ultimately have to decide.
    b.    Facts Relating to Truck’s Deductible
    Billings
    Each of Truck’s policies requires Kaiser to pay a deductible
    for each occurrence and, in most cases, a deductible for certain
    specified loss adjustment expenses. From December 31, 1964
    through December 31, 1968, Kaiser was responsible for a
    $5,000.00 deductible per occurrence (per occurrence deductible)
    plus certain specified loss adjustment expenses. From January 1,
    1968 through December 31, 1968, Kaiser was responsible for a
    15
    $15,000.00 “per-occurrence” deductible plus loss adjustment
    expenses. From January 1, 1969 through December 31, 1973,
    Kaiser was responsible for a $5,000.00 “per-occurrence’’
    deductible plus certain specified loss adjustment expenses. From
    January 1, 1974 through December 31, 1975, Kaiser was
    responsible only for a $5,000.00 per occurrence deductible. From
    January 1, 1976 through March 31, 1981, Kaiser was responsible
    for a $50,000.00 “per-occurrence” deductible plus certain specified
    loss adjustment expenses. From April 1, 1981 through April 1,
    1983, Kaiser was responsible for a $100,000.00 per occurrence
    deductible plus certain specified loss adjustment expenses.
    Under the Convention Truck established in 1987, Truck
    charged and Kaiser paid one per occurrence deductible for the
    Truck policy years 1973-1983. Before this action was filed, Kaiser
    was charged by and had paid to Truck per occurrence deductibles
    of $420,000.00, allocated loss adjustment expense deductibles of
    $916,844.88, and unallocated loss adjustment expense
    deductibles of $59,500.00 for asbestos-related litigation. The
    $420,000.00 per occurrence deductibles were already credited to
    Kaiser. In the event Truck’s 2007 billings for per occurrence
    deductibles are not barred by Kaiser’s defenses, the allocated and
    unallocated expenses paid by Kaiser to Truck shall be credited to
    Kaiser. The expenses paid by Kaiser are subject to Truck’s right
    to a credit, which Kaiser disputes, for $362,776.06 that Kaiser
    received as a result of the Fireman’s Fund settlement agreement.
    Effective July 1, 2004, Truck began allocating to Kaiser a
    pro-rata share of each ABIC settlement. As a result, Kaiser
    funded approximately 10 percent of ABIC settlement payments
    from July 1, 2004 through February 1, 2006.
    16
    In a letter dated August 31, 2004, Kaiser objected to
    Truck’s allocation of indemnity payments to it. In its letter,
    Kaiser selected the 1974 or 1975 Truck policy years to respond to
    ABIC and cited Aerojet, supra, 
    17 Cal.4th 38
     and Armstrong,
    supra, 
    45 Cal.App.4th 1
    , as a basis for its selection.
    In October 2004, Truck sought summary adjudication on its
    claims that ABIC were a single occurrence, that Truck had paid
    the occurrence limits for each primary policy it issued to Kaiser,
    and that Truck thus had no further obligation to defend or
    indemnify Kaiser. (LMI, supra, 146 Cal.App.4th at pp. 652–653.)
    When the trial court granted Truck’s motion in January
    2006, Truck withdrew all defense and indemnity for ABIC,
    effective February 1, 2006. Thereafter, Kaiser incurred 100
    percent of defense and indemnity for each ABIC pending and
    settled after that date.
    As noted above, in a January 9, 2007 decision, this court
    reversed the trial court’s summary adjudication order, holding
    that an “occurrence” for purposes of determining per occurrence
    limits and deductibles meant “injurious exposure to asbestos,”
    and it remanded the case to the trial court for a factual
    determination of how many “occurrences” gave rise to ABIC.
    (LMI, supra, 146 Cal.App.4th at pp. 651, 672.)
    In a January 24, 2008 order, the trial court ruled that each
    asbestos-related bodily injury claim shall be deemed to have been
    caused by a separate and distinct occurrence within the meaning
    of the Truck policies.
    Following the January 2007 LMI decision, Truck
    acknowledged it owed Kaiser a complete defense and indemnity
    under its 1974 policy, retroactive to July 1, 2004, and resumed
    the defense and indemnity of ABIC as of September 1, 2007.
    17
    Kaiser had paid $25,988,284.05 in defense costs and
    $51,464,477.35 in indemnity costs between July 1, 2004 and
    September 1, 2007 for ABIC that were covered under Truck’s
    1974 policy.
    By letter dated July 23, 2007, Truck calculated, billed
    and—from amounts it otherwise owed to Kaiser at that time—
    withheld various sums from its reimbursement payment,
    including $9,521,158.50 in per occurrence deductibles under the
    1974 policy that Truck claimed it was owed by Kaiser.
    Since its July 23, 2007 billing, Truck has continued to bill
    Kaiser for a separate per occurrence deductible on each ABIC
    resolved with payment. Truck billed Kaiser $1,264,000.00 on
    August 12, 2009 (which Kaiser paid on September 10, 2009), and
    $2,245,500.00 on October 4, 2013 (which Kaiser has not yet paid).
    Truck’s July 23, 2007 per occurrence deductibles billing
    was the first time Truck asked Kaiser to pay a separate
    deductible for each claimant, and Kaiser did not object to Truck’s
    per occurrence deductible billing on grounds it was untimely until
    after July 23, 2007.
    The Truck policy issued to Kaiser effective January 1, 1974
    contains the following language concerning Kaiser’s obligation to
    pay a deductible to Truck: “$5,000 shall be deducted from the
    total amount to be paid for all damages which the Insured
    becomes legally obligated to pay on account of each occurrence.”
    Truck filed its second amended complaint in this action on
    August 23, 2007, alleging for the first time (in paragraph 51) that
    Kaiser owed a separate per occurrence deductible for each ABIC.
    For the 1,472 ABIC resolved with payment before August
    23, 2003, four years before Truck filed its second amended
    complaint, Truck withheld deductibles on July 23, 2007 from its
    18
    payment for Kaiser’s reimbursement in the amount of
    $6,629,391.00.
    For the 802 ABIC resolved with payment before October 1,
    2000, four years before Truck filed its first amended complaint
    for declaratory relief, Truck withheld deductibles on July 23,
    2007 from its payment for Kaiser’s reimbursement in the amount
    of $3,235,496.00.
    For the 426 ABIC resolved with payment before April 30,
    1997, four years before Truck filed its original complaint for
    declaratory relief, Truck withheld deductibles on July 23, 2007
    from its payment for Kaiser’s reimbursement in the amount of
    $1,657,003.50.
    c.     Facts Relating to Truck’s Equitable
    Allocation
    i.     Kaiser’s Asbestos Claims
    Kaiser manufactured asbestos-containing products at 10
    different facilities from the 1940s through the 1970s. (LMI, supra,
    146 Cal.App.4th at p. 652.) Sometime in the late 1970s, Kaiser
    began to tender to Truck bodily injury claims resulting from
    exposure to Kaiser’s products containing asbestos. By October
    2004, more than 24,000 claimants had filed products liability
    actions against Kaiser, and Truck’s indemnity payments exceeded
    $50 million.
    ii.   Commencement of This Action
    In April 2001, Truck filed a declaratory relief action
    asserting its aggregate limit policies (1965-1970 and 1980-1983)
    were exhausted, it paid all applicable per occurrence limits on the
    non-aggregate limit policies, and thus had no further duty to
    indemnify Kaiser for asbestos claims. This initial complaint did not
    19
    make any allegations concerning deductibles. Kaiser cross-claimed,
    alleging that all the asbestos claims arose from one occurrence and
    sought a declaration that it was responsible for only one deductible.
    Kaiser also sought a declaration of coverage under the excess
    policies in the event the Truck policies were deemed exhausted.
    (LMI, supra, 146 Cal.App.4th at p. 652.)
    B.    THE CONVENTION
    As noted above, in the 1980s, when Kaiser began to receive
    asbestos claims, California law did not define what constituted an
    “occurrence” with respect to ABIC. Before 1987, Truck set up one
    claim file for each policy year, but did not allocate payments for
    any individual claimant to more than one policy year. Instead,
    Truck used a single date of loss.
    Beginning in 1987, Truck adopted the Convention pursuant
    to which Truck set up a “master” claim file for each policy. Truck
    broke each of Kaiser’s asbestos claims into indemnity and expenses
    and allocated it across the number of years of exposure to Kaiser’s
    products, thereby prorating it into each applicable policy year.
    Under the Convention, Kaiser paid one deductible per policy year
    for the policy years 1973-1983, rather than one deductible per
    occurrence.7
    7      The trial court observed in its Phase I Statement of
    Decision that the Convention benefitted both parties. LMI
    explained, “[u]nder the 1964 policy, Kaiser was responsible for
    the first $5,000 of loss for each ‘occurrence’; by 1981, the per
    occurrence deductible was $100,000. Thus, Kaiser’s share of the
    total asbestos liability increases as the number of occurrences
    increases. Additionally, although asbestos claims against Kaiser
    collectively exceed tens of millions of dollars, many individual
    20
    Although the parties adhered to the Convention, they never
    reached an express agreement concerning the definition of
    “occurrence” and hence a final resolution of how deductibles would
    be allocated. Instead, during the time the Convention was in effect,
    the parties agreed it was an interim arrangement not in writing,
    and that the definition of an “occurrence” was an unresolved
    question of law.
    As noted above, at the time the Convention was initiated,
    what constituted an “occurrence” for purposes of calculating per
    occurrence limits and per occurrence deductibles with respect to
    ABIC was an open legal question. Thus, Truck and Kaiser were
    uncertain of how to bill the losses and how to calculate any
    deductibles. Testimony at the Phase I trial showed Truck
    instigated the Convention and Kaiser, under a unilateral
    reservation of rights, agreed to the Convention’s procedure for
    deductible billing purposes because it benefitted from it.
    For example, in a June 1991 letter concerning deductible
    billings, Kaiser stated that “Kaiser hereby reserves its right to
    further consider and, as may be appropriate with respect to policy
    terms and conditions, to challenge the convention established by
    claims apparently are within the applicable deductibles. Thus, if
    each claim is treated as a separate occurrence, Kaiser may have
    no coverage for a substantial number of claims.” (LMI, supra, 146
    Cal.App.4th at p. 653, fn. 2.) In addition, the Convention
    benefitted Truck’s reinsurers because if Truck’s indemnity
    payments were based upon a separate occurrence for each
    claimant, the payments would likely not implicate the reinsurers’
    obligations because most asbestos claims would be settled for
    small amounts. Under Truck’s reinsurance agreement Truck paid
    $150,000 for each occurrence and the reinsurers paid everything
    in excess of that.
    21
    [Truck] of combining all asbestosis claims into one master claim
    per policy period[.]” Kaiser’s general counsel Carl Pagter stated
    that under the Convention, the parties treated the deductible as
    arising from a single claim. The parties recognized the issue was
    open until decided by a court. Kaiser, however, realized at some
    time in the future the legal issue of what constituted an occurrence
    would be decided.
    Truck acquiesced (as stated by Truck employee Dennis
    Patterson) that “there was a general understanding that this was a
    mutually agreed-upon method of allocating and billing for Kaiser’s
    asbestos claims, and that if, . . . the case law changed, that we may
    have to do it some different way. So I think there was always an
    understanding that both parties reserved the right.” Truck sought
    and received concurrence in the Convention from its reinsurers.
    During the course of this coverage action, Kaiser took
    different positions on the number of occurrences giving rise to
    asbestos claims, including the position that such claims arose from
    a single occurrence, or that asbestos claims arose from a small
    number of occurrences.
    Effective July 1, 2004, Truck began allocating to Kaiser a
    pro-rata share of each asbestos settlement. As a result, Kaiser
    funded approximately 70 percent of settlement payments from July
    1, 2004 through February 1, 2006.
    1.    Truck’s October 2004 Summary Judgment
    Motion
    In October 2004, Truck sought summary judgment on its
    exhaustion claim. (LMI, supra, 146 Cal.App.4th at p. 652.) Truck
    argued the per occurrence limit in the policies capped its liability
    for injuries arising from any one occurrence. (Ibid.) Furthermore, it
    argued, because it had paid the occurrence limits for each primary
    22
    policy, it had no further indemnification obligation to Kaiser. (Id.
    at p. 653.) Truck based this argument on the Convention’s one-
    occurrence-per year-structure and on its assertion that the
    occurrence was “‛the design, manufacture and distribution by
    Kaiser and its subsidiaries of asbestos-bearing products,’” rather
    than each claimant’s exposure to asbestos. (Ibid.) As a result, it
    contended the indemnity payments made exceeded the per
    occurrence limits in the policies. (Ibid.) Truck also relied on the
    parties’ course of conduct in paying a single deductible per policy
    year and asserted this conduct supported its interpretation of the
    policies. (Ibid.) Kaiser agreed the asbestos claims resulted from a
    single annual occurrence, but contended that neither it nor Truck
    ever believed they reached an agreement on the number-of-
    occurrences issue and that Kaiser retained the right to challenge it.
    (Ibid.)
    The trial court granted Truck’s motion, finding that “as a
    matter of law, . . . the manufacture and decision to place asbestos
    into products by the Kaiser entities constituted a single occurrence
    under the applicable policies.” (LMI, supra, 146 Cal.App.4th at p.
    655.) The trial court concluded the policies were exhausted. (Ibid.)
    After the trial court’s January 2006 ruling, Truck withdrew its
    defense and indemnity from Kaiser as of February 1, 2006.
    2.    The LMI Decision and the Meaning of an
    “Occurrence”
    As noted above, in LMI, this court disagreed with the trial
    court’s summary judgment ruling on the “occurrence” issue, and
    rejected Truck’s position. (LMI, supra, 146 Cal.App.4th at pp. 651,
    672.) After noting that the dispute centered on the policies dating
    from 1971 to 1980 (which contained no aggregate limits, only per
    occurrence limits), this court held each “occurrence” under the
    23
    policy was the claimant’s exposure to Kaiser’s asbestos containing
    products, not Kaiser’s manufacture of asbestos containing
    products. (Id. at pp. 660.) “[W]e conclude that the parties did not
    understand or intend ‘event’ to mean “‘anything that happens,’”
    including ‘the conscious inclusion of asbestos in products
    manufactured and distributed by the policyholder.’ . . . . Instead,
    we conclude that the parties intended ‘event’ to mean an
    identifiable, single injury-causing episode—an ‘accident’ under the
    older CGL form—as distinct from ‘continuous or repeated
    exposure.’” (Id. at p. 662.) The case was remanded for a factual
    determination of the number of occurrences. (Id. at p. 672.)
    Following LMI, Truck resumed its indemnity obligations to
    Kaiser retroactively to July 1, 2004. Also based on LMI, Truck filed
    its second amended complaint in August 2007, asserting it was
    entitled to payment of a separate deductible for each asbestos
    claim it had paid or would pay, and that this method of deductible
    assessment accrued with the 2007 LMI decision. This was the first
    time Truck assessed a deductible for each claimant, and Truck
    withheld $9,521,158.20 in per occurrence deductibles from
    amounts owed to Kaiser. This included $6,629,391.00 in
    deductibles that predated Truck’s second amended complaint by
    more than four years.
    In response to Truck’s assessment of the deductibles, Kaiser
    filed a third amended cross-complaint, asserting Truck had not
    exhausted the policy limits for asbestos claims, Kaiser was entitled
    to select an insurance policy during any triggered policy year
    pursuant to Armstrong, and Kaiser was only responsible for the
    deductible and/or loss expenses per the policies.
    24
    In January 2008, pursuant to the holding of LMI, the trial
    court confirmed that each asbestos claim would be deemed to have
    been caused by a separate occurrence.
    C.    PHASE I TRIAL
    Kaiser asserted Truck’s claims for deductibles accrued at the
    time each claim was paid, and not with the January 2007 decision
    in LMI. As a result, Kaiser contended any claim for a deductible
    assessed more than four years before Truck’s August 23, 2007
    second amended complaint was untimely under the four-year bar
    of Code of Civil Procedure section 337. Truck asserted that Kaiser’s
    acquiescence in Truck’s billing Convention and the parties’
    respective reservations of rights with respect to the deductible in
    effect barred any statute of limitations defense.
    1.     Evidence
    The Phase I trial commenced in November 2014 and
    addressed the issue of when Truck’s claim for unpaid deductibles
    accrued under the policies as interpreted by LMI. The trial was
    conducted based upon stipulated facts, documentary evidence, and
    deposition testimony.
    2.     Trial Court Ruling
    In its statement of decision, the trial court identified a
    “breach” as the non-payment of a per occurrence deductible under
    the 1974 policy. The trial court reasoned the parties were operating
    under the Convention, treating each claim as arising from one
    occurrence, and billing one deductible per policy year. The court
    observed that with respect to the right to challenge the deductible
    calculation, the parties agreed “both sides were willing to go along
    without prejudice to each other’s rights in the future.” Further, each
    25
    party believed the calculation, whether annual or per occurrence,
    was an unresolved question of law resulting from ambiguities in
    the policy. Finally, Kaiser did not challenge the Convention before
    2007.
    As a result, the trial court concluded that deductibles for
    individual claims “could not have been ‘available’ until this critical
    issue had been decided by the Court of Appeal [in LMI], and could
    not have accrued until that time.” The trial court observed that
    LMI identified the issue— “the meaning of ‘occurrence’” in a CGL
    policy “as applied to bodily injuries caused by exposure to
    asbestos”—as one of “first impression.”
    The trial court found there was no consequence to the lack of
    a tolling agreement because one would only have been required if
    the claims had in fact accrued before LMI. Even if the statute of
    limitations began to run at a time earlier than LMI, the court
    found the parties’ reservation of rights essentially operated as a
    tolling agreement. Because it determined the claim did not accrue
    until LMI, the trial court found equitable estoppel did not apply
    and the question of waiver was moot. “The weight of evidence
    before the court shows that both Truck and Kaiser were always
    operating under the assumption that the convention controlled the
    number of occurrences, and hence, the number of deductibles—
    notwithstanding the mutual view held by both parties that the
    ‘number of occurrences’ issue was unresolved and would ultimately
    have to be decided by the courts.”
    Finding the parties did not dispute Truck’s calculation of
    $9,521,158.50 in offsets, the trial court ruled Truck properly
    assessed deductibles Kaiser owed for all claims settled before
    August 23, 2003 (four years before the filing of Truck’s second
    amended complaint).
    26
    D.    STANDARD OF REVIEW
    Where, as here, the relevant facts are undisputed, it is a
    question of law whether a claim is barred by the statute of
    limitations. Accordingly, we apply the de novo standard of review.
    (Aryeh v. Canon Business Solutions, Inc. (2013) 
    55 Cal.4th 1185
    ,
    1191.)
    E.    DISCUSSION
    1.     Truck’s Claim for Deductibles Accrued
    When Truck Paid or Otherwise Resolved
    Each Claim
    The parties dispute when the claim for each deductible
    accrued. Kaiser asserts it was when each deductible was or could
    have been assessed on a claim. Truck asserts its claims did not
    accrue until LMI defined an “occurrence.” We agree with Kaiser.
    The statute of limitations is a legislatively prescribed time
    period to bring a cause of action. (Gilkyson v. Disney Enterprises,
    Inc. (2016) 
    244 Cal.App.4th 1336
    , 1341.) It aims to promote the
    diligent assertion of claims and “‘ensure defendants the
    opportunity to collect evidence while still fresh,’” while providing
    “‘repose and protection from dilatory suits once excess time has
    passed.’ [Citation.]” (Ibid.) “Under the statute of limitations, a
    plaintiff must bring a cause of action within the limitations period
    applicable thereto after accrual of the cause of action. [Citations.]”
    (Norgart v. Upjohn Co. (1999) 
    21 Cal.4th 383
    , 397.)
    For breach of a written contract, the period is four years from
    the time the claim accrues. (Code Civ. Proc., § 337.) The elements
    of a cause of action for breach of contract are: the contract,
    plaintiff’s performance or excuse for nonperformance, defendant’s
    breach, and the resulting damages to plaintiff. (Coles v. Glaser
    27
    (2016) 
    2 Cal.App.5th 384
    , 391.) Generally, a claim for breach of
    contract accrues when all these elements have occurred. (Howard
    Jarvis Taxpayers Assn. v. City of La Habra (2001) 
    25 Cal.4th 809
    ,
    815 [statute of limitations runs from occurrence of the last element
    essential to the cause of action].) To determine whether a breach
    has occurred, we look to the terms of the contract. (Weddington
    Productions, Inc. v. Flick (1998) 
    60 Cal.App.4th 793
    , 811.)
    Pursuant to the language of the policies, “$5,000 shall be
    deducted from the total amount to be paid for all damages which
    the Insured becomes legally obligated to pay on account of each
    occurrence.” (Emphasis added.) Thus, Truck’s claim for a deductible
    accrued when Truck became obligated to indemnify Kaiser and
    assess a deductible. (See, e.g., Specialty Nat’l Ins. Co. v. U-Save
    Auto Rental of Am., Inc. (M.D. Fla. Nov. 12, 2008, Civ. A. No. 8:07-
    cv-878-33MAP) 2008 U.S.Dist. Lexis 94931, pp. 15–16 (Specialty).)
    Specialty involved the timeliness of an insurer’s suit for unpaid
    deductibles. (Id. at p. 8.) The insurer argued it could not have
    brought suit against the insured until it demanded reimbursement
    of the deductibles and the insured refused payment, because at
    that time the insurer would be damaged. (Id. at pp. 11–12.)
    Specialty held the deductibles claim accrued when the insurer
    settled the claims—nothing in the contract prevented the insurer
    from demanding payment at any time. Its claim for deductibles due
    before the statute of limitations bar date was therefore untimely.
    (Id. at pp. 17–18) The court observed that statutes of limitation
    were designed to prevent parties from sleeping on their rights. (Id.
    at p. 17.) Similarly, Hahn Automotive Warehouse, Inc. v. Am.
    Zurich Ins. Co. (2012) 
    18 N.Y.3d 765
    , 768-769 [
    967 N.E.2d 1187
    ]
    (Hahn) involved the inadvertent failure to bill for deductibles not
    discovered until an audit performed six years after the statute of
    28
    limitations had expired. Hahn held the claim accrued with the
    right to demand payment. (Id. at pp. 770–771.)
    Under this authority, and Truck’s policy language, Truck’s
    claim for deductibles arose at the time it first made indemnity
    payments for a claim, whether by settlement or judgment, unless
    the parties agreed to toll the statute of limitations or there was a
    waiver of the statute of limitations by Kaiser.
    2.     LMI Did Not Revive Stale Claims
    Kaiser asserts LMI was retroactive and did not create a new
    deductible claim or revive old claims. According to Kaiser, Truck
    always had the ability to charge Kaiser a deductible for each ABIC
    under the language of its policies; LMI did not create that right.
    We agree.
    “‘The general rule is that judicial decisions are given
    retroactive effect. [Citation.] Departure from that rule is limited to
    those narrow circumstances in which considerations of fairness and
    public policy preclude retroactivity. . . .’ [Citation.]” (Doe v. San
    Diego-Imperial Council (2015) 
    239 Cal.App.4th 81
    , 90.) “The
    exception to the principle of retroactivity is inapplicable where . . .
    a court is deciding a legal question in the first instance, rather
    than overturning prior appellate decisions. [Citation.]” (Id. at p. 91;
    see also Alvarado v. Dart Container Corp. of California (2018) 
    4 Cal.5th 542
    , 573 [judicial decision retroactive where party “cannot
    claim reasonable reliance on settled law.”].)
    Here, LMI decided an issue of first impression. (LMI, supra,
    146 Cal.App.4th at p. 651 [the meaning of “occurrence” as used in
    per occurrence limits and deductibles in a CGL policy as applied to
    bodily injuries caused by exposure to asbestos is “an issue of first
    impression in this state.”].) Truck, therefore, could not have
    reasonably relied on contrary authority prior to the decision in LMI
    29
    because no such authority existed. Accordingly, we agree with
    Kaiser that the holding in LMI (“occurrence” as used in the policies
    at issue with respect to per occurrence limits and deductibles
    means injurious exposure to asbestos) applies retroactively.
    3.    A “Reservation of Rights” Did Not Toll the
    Four-Year Statute of Limitations
    a.    A Reservation of Rights, Without
    More, Is Not a Tolling Agreement
    We reject Truck’s assertion that the reservation of rights
    tolled the running of the statute of limitations.8 A statute of
    limitations may be tolled by express agreement of the parties.
    (See, e.g., Wind Dancer Production Group v. Walt Disney Pictures
    (2017) 
    10 Cal.App.5th 56
    , 79.) Here, there is no such express
    8     Reservations of rights commonly occur in the insurance
    context when an insurer notifies its insured that it will furnish a
    defense to the injured party’s suit against the insured but at the
    same time reserves the right to refuse to indemnify the insured
    against any judgment on the ground that the claim was not
    covered under the policy, and to withdraw its defense upon the
    same ground. (Truck Ins. Exchange v. Superior Court (1996) 
    51 Cal.App.4th 985
    , 994.) Such a reservation of rights prevents
    waiver of coverage defenses: the insurer meets its obligation to
    furnish a defense without waiving its right to assert coverage
    defenses against the insured later. (Blue Ridge Ins. Co. v.
    Jacobsen (2001) 
    25 Cal.4th 489
    , 497–498.) Thus, in that context a
    reservation of rights is used to separate the insurer’s indemnity
    obligation from its defense obligation and does not involve the
    statute of limitations because the insured’s claim has already
    accrued at the time of litigation and the statute is no longer
    running. Such an open-ended reservation of rights in that context
    has no effect upon the statute of limitations.
    30
    agreement, and furthermore, the record does not demonstrate the
    parties agreed to such an implied term. “‘The only distinction
    between an implied-in-fact contract and an express contract is
    that, in the former, the promise is not expressed in words but is
    implied from the promisor’s conduct. [Citations.] Under the
    theory of a contract implied in fact, the required proof is
    essentially the same as . . . [on an] express contract, with the
    exception that conduct from which the promise may be implied
    must be proved. [Citation.]’” (Chandler v. Roach (1957) 
    156 Cal.App.2d 435
    , 440, emphasis omitted.) Indeed, the record is
    silent on whether the parties intended to toll or waive any statute
    of limitations with respect to the deductibles. At most, the
    evidence presented details the parties’ understanding of the
    Convention and its purpose and effect. Other than the parties’
    joint realization that at some point the law would be clarified,
    there is nothing further. This is consistent with the fact that the
    Convention was, in the words of Kaiser, “not really an
    agreement” but merely a procedure under which they agreed to
    operate.
    Nonetheless, Truck asserts that final collection of the
    deductibles was tolled until the time for performance ripened with
    LMI’s ruling on the definition of an “occurrence.” Because
    deductibles would have normally accrued with the settlement of
    each claim, Truck asserts the reservation of rights rendered the
    policies executory contracts because each deductible was subject to
    later change. (See Civ. Code, § 1661 [executed contract is one in
    which the object has been fully performed; all others are
    executory]; State Comp. Ins. Fund. v. WallDesign, Inc. (2011) 
    199 Cal.App.4th 1525
    , 1529-1530 [statute of limitations does not run on
    an executory contract until the time for full performance has
    31
    arrived.].) Thus, Truck argues the time for “full performance,”
    namely, identification of the method of deductible assessment as
    being per-claim, and accrual of the statute of limitations, did not
    occur until the 2007 LMI decision.
    Because Truck’s approach reads the Convention too broadly
    and finds no support in the record, we disagree. Truck relies on
    Schuler v. Community First National Bank (Wyo. 2000) 
    999 P.2d 1303
     for the proposition that “[a]s a general rule, if the parties
    mutually adopt a mode of performing their contract differing from
    its strict terms or if they mutually relax the contract’s terms by
    adopting a loose mode of executing them, neither party can go back
    upon the past and insist upon a breach because the contract was
    not fulfilled according to its letter. [Citation.]” (Id. at p. 1305, fn. 1;
    see also Ghirardelli v. Peninsula Properties Co. (1940) 
    16 Cal.2d 494
    , 498 (Ghirardelli) [where parties agreed no payment due until
    account of trustee rendered, statute of limitations did not run].)
    That is not the case here. We see no reason why the parties, had
    they actually agreed to toll the statute of limitations, would not
    enter into a written agreement to that effect or bring a declaratory
    relief action. Further, unlike Ghirardelli, there was no agreement
    to defer performance.
    b.     The Discovery Rule Does Not Apply
    In an attempt to avoid this result, Truck asserts the
    discovery rule and claims it only discovered after LMI that it was
    injured by the Convention and thus the four-year statute of
    limitations did not begin to run until LMI. (See, e.g., April
    Enterprises, Inc. v. KTTV (1983) 
    147 Cal.App.3d 805
    , 831 [in
    breach of contract action, claim accrued when plaintiffs discovered
    they were harmed].) The discovery rule “may be applied to
    breaches [of contract] which can be, and are, committed in secret
    32
    and, moreover, where the harm flowing from those breaches will
    not be reasonably discoverable by plaintiffs until a future time.”
    (Id. at p. 832; Gryczman v. 4550 Pico Partners, Ltd. (2003) 
    107 Cal.App.4th 1
    , 5 [discovery rule applicable to breach of contract
    action where defendant “not only breached the contract ‘within the
    privacy of its own offices’ but the act which constituted the
    breach . . . was the very act which prevented plaintiff from
    discovering the breach.”].)
    Under the discovery rule, the plaintiff must show that,
    “despite diligent investigation of the circumstances of the injury, he
    or she could not have reasonably discovered facts supporting the
    cause of action within the applicable statute of limitations period.”
    (Fox v. Ethicon Endo-Surgery, Inc. (2005) 
    35 Cal.4th 797
    , 809.)
    But the discovery rule applies to ignorance of the facts, not
    the law. (Love v. Fire Ins. Exchange (1990) 
    221 Cal.App.3d 1136
    ,
    1144-1145 [knowledge of the facts, rather than knowledge of
    available legal theories or remedies, starts the statute of
    limitations].) Our Supreme Court’s decision in Jolly v. Eli Lilly &
    Co. (1988) 
    44 Cal.3d 1103
     (Jolly) is closely on point. In Jolly, the
    plaintiff delayed bringing suit for injuries resulting from her
    mother’s use of diethylstilbestrol (DES), while plaintiff was in
    utero, because she could not identify and name the specific
    manufacturer of the drug supplied to her mother. (Id. at pp. 1107–
    1108.) Appellate case law prevailing at the time plaintiff discovered
    the facts creating her cause of action held a plaintiff must identify
    the manufacturer of the drug. (Id. at pp. 1114, 1116.) In Sindell v.
    Abbott Laboratories (1980) 
    26 Cal.3d 588
     (Sindell), however, our
    Supreme Court held a plaintiff who was harmed by DES and who
    was unable to identify the particular manufacturer could state a
    cause of action by joining defendants that manufactured a
    33
    substantial percentage of the market for the drug. (Id. at pp. 612–
    613; Jolly, supra, at p. 1108.) In Jolly, the plaintiff filed her
    complaint less than one year after Sindell, but more than one year
    after her action would ordinarily be deemed to have accrued. (Jolly,
    supra, at pp. 1108, 1113–1114.) She therefore attempted to avoid
    the bar of the one-year statute of limitations by arguing that the
    issuance of the court’s opinion in Sindell was what started the
    limitations period running. (Jolly, supra, at p. 1114.) The Jolly
    court rejected her argument, holding the decision in Sindell did not
    constitute a “fact” that activated the one-year statute of
    limitations: “Sindell demonstrated the legal significance of facts
    already known to plaintiff. The statute had started to run for
    plaintiff well before Sindell was decided.” (Jolly, supra, at p. 1115.)
    Like the plaintiff in Jolly, Truck was fully informed of the
    facts, precluding application of the discovery rule. The only
    unknown was the legal issue of how California courts would
    construe “occurrence” with respect to calculating deductions for
    ABIC. Truck’s argument incorrectly asserts that uncertainty about
    a legal issue has the same effect as ignorance of factual issues,
    such as the existence of an injury.
    c.    There Is No Equitable Tolling
    Truck further asserts that under the doctrine of equitable
    tolling, the statute of limitations did not run because Kaiser
    obtained the benefits of lower deductible payments and it cannot
    equitably avoid the burdens of LMI. Equitable tolling has no place
    here. Equitable tolling is a judicially created, nonstatutory doctrine
    that suspends or extends a statute of limitations as necessary to
    ensure fundamental practicality and fairness. (Saint Francis
    Memorial Hospital v. State Dept. of Public Health (2020) 
    9 Cal.5th 710
    , 716–717.) “The doctrine applies ‘occasionally and in special
    34
    situations’ to ‘soften the harsh impact of technical rules which
    might otherwise prevent a good faith litigant from having a day in
    court.’ [Citation.]” (Id. at pp. 719–720.) There is no reason to apply
    the doctrine where, as here, the parties were fully aware that
    controlling law was uncertain, were sophisticated and assisted by
    competent counsel, and could have protected their right to bring
    suit by either bringing suit or executing a tolling agreement.
    d.    Kaiser is Not Equitably Estopped to
    Assert the Statute of Limitations
    Finally, Kaiser is not equitably estopped to assert the bar of
    the statute of limitations merely because it agreed to the
    Convention. The doctrine of equitable estoppel is founded on
    principles of equity and fair dealing. (Krolikowski v. San Diego City
    Employees’ Retirement System (2018) 
    24 Cal.App.5th 537
    , 564.) It
    provides that a party may not deny the existence of facts if that
    party has intentionally led others to believe a particular
    circumstance to be true and to rely upon that belief to their
    detriment. (Ibid.) “‘“‘Generally speaking, four elements must be
    present in order to apply the doctrine of equitable estoppel: (1) the
    party to be estopped must be apprised of the facts; (2) he [or she]
    must intend that his [or her] conduct shall be acted upon, or must
    so act that the party asserting the estoppel had a right to believe it
    was so intended; (3) the other party must be ignorant of the true
    state of facts; and (4) he or she must rely upon the conduct to his
    [or her] injury.’” . . .’ [Citation.]” (Id. at pp. 564–565.) Nothing in
    the record supports an assertion that Truck was unaware of the
    true state of the relevant facts. Moreover, Truck knew the Supreme
    Court had yet to define “occurrence” in the context of calculating
    deductibles for ABIC.
    35
    4.     Code of Civil Procedure Section 360.5
    Requires a Writing, Renewed Every Four
    Years, for Waiver of the Statute of
    Limitations
    Kaiser correctly notes that waiver of the statute of
    limitations cannot, as Truck asserts, be created by implication.
    Code of Civil Procedure section 360.5 states, in relevant part: “No
    waiver shall bar a defense to any action that the action was not
    commenced within the time limited by this title unless the waiver
    is in writing and signed by the person obligated. No waiver
    executed prior to the expiration of the time limited for the
    commencement of the action by this title shall be effective for a
    period exceeding four years from the date of expiration of the time
    limited for commencement of the action by this title and no waiver
    executed after the expiration of such time shall be effective for a
    period exceeding four years from the date thereof, but any such
    waiver may be renewed for a further period of not exceeding four
    years from the expiration of the immediately preceding waiver.”
    Truck’s reliance on Don Johnson Productions, Inc. v. Rysher
    Entertainment LLC (2012) 
    209 Cal.App.4th 919
     (Don Johnson) is
    misplaced. Truck relies on Don Johnson for the proposition that an
    “equitable tolling agreement can exist independent of a written
    waiver of the statute of limitations.” In Don Johnson, the court
    held section 360.5 applies to waivers of the statute of limitations,
    not tolling agreements; thus, it was not necessary for the parties to
    renew their written tolling agreement after four years. (Don
    Johnson, supra, at p. 930.) Here, however, as discussed in sections
    E.3.a and E.3.c, ante, there is no evidence in the record that the
    parties intended to toll the statute of limitations, and, in any event,
    there is no reason to apply the equitable tolling doctrine here.
    36
    Accordingly, for the statute of limitations to permit the assertion of
    pre-2003 claims, Kaiser must have affirmatively and in writing
    waived the statute. The record contains no such written waiver.
    5.     Truck’s Claimed Setoff Can Apply Only to
    Those Deductibles Not Barred by the
    Statute of Limitations
    a.    Factual Background and Trial Court
    Ruling
    In its Third Amended Complaint, Truck’s first cause of
    action sought a declaratory judgment “that it must pay a net total
    of its per[ ]occurrence limit minus the applicable deductible for any
    ABIC, and that it is not liable to Kaiser . . . for any additional
    amounts.” In its answer to Kaiser’s Third Amended Cross
    Complaint, Truck asserted as its tenth affirmative defense that
    “[t]o the extent Truck may be held liable to Kaiser, Truck is
    entitled to set off from any such liability amounts owed to Truck by
    Kaiser.” In its Phase I trial brief, Truck alleged that “[w]ith no
    breach and no statute of limitations bar, Truck was entitled to
    offset the full $9,521,158.50 for a $5,000 deductible per ABIC
    under the 1974 policy. Truck acknowledges that with this outcome
    it owes Kaiser $613,968.82, in reimbursement for allocated and
    unallocated expenses Kaiser had paid under policies other than the
    1974 policy. . . . Thus, [Truck asserts,] because [it] was entitled to
    offset the whole $9,521,158.50 in deductible billings, [it] owes
    Kaiser [only] $613,968.82, representing allocated and unallocated
    loss expenses Kaiser previously paid Truck.” The trial court found
    Truck’s setoff claim “could not have been ‘available’ until [LMI] and
    could not have accrued until that time.” The court concluded that
    Truck properly offset amounts for ABIC settled before 2003.
    37
    b.      Truck’s Setoff Claim Does Not Revive
    Stale Deductible Claims But Only
    Permits Offset Against Post-2003
    Deductibles
    Both parties assert waiver with respect to the setoff issue.
    Truck asserts Kaiser’s failure to address the setoff nature of its
    deductible claim waives its limitations period argument, which
    operates differently for a setoff defense, while Kaiser argues Truck
    did not raise the setoff issue at trial. As discussed above, the record
    demonstrates the issue was raised by both parties and ruled on by
    the trial court.
    In any event, Truck’s setoff claim does not revive pre-2003
    deductibles or permit the parties to revisit those claims in any
    fashion. Code of Civil Procedure section 431.70 allows the
    offsetting of cross-demands that have coexisted at some point in
    time, notwithstanding that one of the claims is now barred by the
    statute of limitations. (Jones v. Mortimer (1946), 
    28 Cal.2d 627
    ,
    633; Sunrise Produce Co. v. Malovich (1950) 
    101 Cal.App.2d 520
    ,
    523 [applying previous version of section 431.70].) Section 431.70
    provides that where cross-demands for money exist between
    plaintiff and defendant, defendant “may assert in the answer the
    defense of payment.”9 In general, a setoff prevents the superfluous
    9     Code of Civil Procedure section 431.70 provides: “Where
    cross-demands for money have existed between persons at any
    point in time when neither demand was barred by the statute of
    limitations, and an action is thereafter commenced by one such
    person, the other person may assert in the answer the defense of
    payment in that the two demands are compensated so far as they
    equal each other, notwithstanding that an independent action
    asserting the person’s claim would at the time of filing the
    38
    exchange of money between parties and is asserted at the end of
    litigation. (Los Angeles Unified School Dist. v. Torres Construction
    Corp. (2020) 57 Cal.App.5th. 480, 500.) The affirmative defense of
    setoff is equitable in nature. (Granberry v. Islay Investments (1995)
    
    9 Cal.4th 738
    , 743–744.)
    Code of Civil Procedure section 431.70 does not toll running
    of statutes of limitations, but permits assertion of setoff—if at the
    time of the assertion of underlying claim—the statute of
    limitations has not run. (See Safine v. Sinnott (1993) 
    15 Cal.App.4th 614
    , 618-619.) In this context, a defendant may use
    setoff only “defensively to defeat the plaintiff’s claim in whole or in
    part[,]” but may not use setoff offensively as an independent basis
    for relief. (Construction Protective Services, Inc. v. TIG Specialty
    Ins. Co. (2002) 
    29 Cal.4th 189
    , 197–198.) “[T]o the extent a
    defendant seeks affirmative relief, the applicable statute of
    limitations applies to the defendant’s [setoff] claim, just as it would
    if the defendant were asserting its claim in an independent action.”
    (Id. at p. 198)
    The trial court’s calculations were based upon its finding
    that none of the deductibles were time-barred. As we have
    concluded Truck may not revisit pre-August 2003 deductibles
    because they are time-barred, Truck cannot rely on Code of Civil
    Procedure section 431.70 to revive these claims. Truck may,
    however offset against deductibles accruing after 2003; such
    deductibles must be recalculated as per occurrence deductibles.
    answer be barred by the statute of limitations. If the cross-
    demand would otherwise be barred by the statute of limitations,
    the relief accorded under this section shall not exceed the value of
    the relief granted to the other party.”
    39
    F.    Conclusion
    Truck’s withholding of deductibles in the amount of
    $6,629,391 for the 1,472 ABIC claims resolved before August 23,
    2003 was improper; Truck’s claim to recover those deductibles is
    time-barred. Accordingly, the portion of the final judgment relating
    to Phase I, in which the trial court rendered judgment “in favor of
    plaintiff and cross-defendant Truck and against defendant and
    cross-complainant Kaiser with respect to Truck’s Third Amended
    Complaint (for Declaratory Relief) and Kaiser’s Fourth Amended
    Cross-Complaint according to the Phase One Decision” is reversed.
    The matter is remanded to the trial court for further proceedings
    consistent with this opinion.
    PHASE II: ALLOCATION TO NON-1974 PRIMARY
    POLICIES
    In Phase II, Truck sought an order permitting it to allocate
    defense and indemnity payments for claims under its 1974
    primary policy (which has no aggregate limit) across all of its
    triggered primary policies, including those with aggregate limits.
    The trial court denied relief. The issue on appeal is whether,
    consistent with Armstrong, Truck can obtain what is essentially
    intra-insurer contribution from itself.
    As noted above, Armstrong holds that once a policy is
    triggered, the policy obligates the insurer to pay “all sums” which
    the insured shall become liable to pay as damages. (Armstrong,
    supra, 45 Cal.App.4th at p. 105.) With a long-tail injury, this may
    include damages attributable to other policy periods. (Ibid.) In
    that case, the insured may elect to seek indemnity under a single
    policy with adequate policy limits, and if such policy covers “all
    sums” for which the insured may be liable, the insurer may be
    40
    held liable up to the policy limits. (Id. at p. 50.) An insured may
    obtain full indemnification and defense from one insurer, leaving
    the selected insurer to seek equitable contribution from other
    insurers covering the same loss. (Id. at p. 52.) Kaiser selected
    Truck’s 1974 no-aggregate limits policy under Armstrong.
    ICSOP addressed the scope of ICSOP’s obligations as
    excess insurer to the Armstrong-selected 1974 policy and the
    attachment point of ICSOP’s excess policies. (ICSOP, supra, at
    pp. 20–21.) As explained below, the ICSOP decision was the
    starting point for Truck’s arguments in Phase II.
    At the Phase II trial, Truck asserted it could allocate
    indemnity to its other policy years—apparently to access
    reinsurance funds associated with those other policies and access
    excess insurance above those policies. Kaiser, on the other hand,
    believed Truck’s proposal would disadvantage it because it would
    exhaust the aggregate-limit policies, and perhaps the excess
    policies above them, thereby reducing the amount of insurance
    available to Kaiser and the asbestos claimants. The trial court
    refused to grant Truck the relief it sought. We affirm.
    I.    FACTUAL BACKGROUND
    As noted above, in July 2004, Truck started to allocate to
    Kaiser a pro-rata share of each asbestos settlement, resulting in
    Kaiser shouldering approximately 70 percent of the settlement
    payments during the period from July 1, 2004 to February 1,
    2006. Kaiser responded to Truck’s action by selecting the no-
    aggregate limit 1974 policy pursuant to Armstrong to respond to
    asbestos claims, asserting Truck was obligated to indemnify it for
    “all sums” due.
    Following the LMI decision in 2007, Truck’s Second
    Amended Complaint asserted the right to equitably allocate
    41
    payments for each occurrence among all triggered Truck policies.
    Kaiser’s Third Amended Cross-Complaint asserted that ICSOP,
    which provided excess insurance to the Truck 1974 policy, was
    responsible to pay all amounts in excess of the 1974 policy’s per
    occurrence limit of $500,000.
    A.    The 2013 ICSOP Decision
    In ICSOP, Kaiser argued that after the 1974 Truck policy
    responded to an individual claim by paying its per occurrence
    limit of $500,000, ICSOP was obligated to indemnify Kaiser for
    amounts in excess of $500,000 up to the $5,000,000 per
    occurrence limit of the ICSOP policy. (ICSOP, supra, pp. 6–7.)
    ICSOP, on the other hand, argued that because the ABIC
    potentially trigger up to 19 policy periods, “the policy limits for
    these 19 separate policy periods must be ‘stacked’ 10 such that
    [   ]
    ‘not only must the Truck $500,000 [per occurrence] limit in the
    1974 policy period be exhausted, but so must all of Truck’s
    primary limits in its other eighteen annual policy periods’” before
    its policy attached. (Id. at pp. 15, 34.) Thus, ICSOP argued, while
    the 1974 primary policy has been exhausted as to many claims
    that exceed the $500,000 per occurrence limit, primary policies
    for other years remain unexhausted. (Id. at pp. 22–23.) ICSOP
    contended that it has “no indemnity obligations with regard to
    any asbestos bodily injury claims until the per occurrence limits
    10    “Stacking” occurs when more than one policy is triggered by
    an occurrence. Each policy year can be called upon to respond to
    the claim up to the full limits of that policy. The limits of each
    policy triggered by an occurrence are added together to the
    determine the amount of coverage available for the claim.
    (ICSOP, supra, at p. 10, fn. 4.)
    42
    of each of Truck’s annual policies . . . have been exhausted.” (Id.
    at p. 23, original emphasis.)
    In ICSOP, this court determined that horizonal exhaustion
    applied to the primary policies, in the sense that ICSOP’s excess
    policy did not attach until all collectible primary policies were
    exhausted. (ICSOP, supra, at p. 24.) Thus, ICSOP’s excess
    liability was “excess to all other collectible primary insurance—
    whether for 1974 or any other year[.]” (Id. at p. 18.) “[T]he
    [ICSOP] policy does not attach immediately upon a loss, but only
    after all available primary insurance has been exhausted.” (Id. at
    p. 19.)
    ICSOP then noted that in Continental Insurance, the
    Supreme Court endorsed an “all sums with stacking” rule for
    long-tail injuries. Continental Insurance reasoned that stacking
    suited continuous loss injuries. (Continental Insurance, 
    supra,
     55
    Cal.4th at pp. 201–202.) ICSOP, however, concluded the rule
    would not apply to the Truck policies because they prohibited
    stacking—their language limited recovery to $500,000 “per
    occurrence.” (ICSOP, supra, at pp. 32–33.)
    ICSOP concluded that the Truck policies were exhausted
    (as to any given claim) after a claim was paid up to the single
    policy limit, even though a claim was spread across multiple
    policy periods. (ICSOP, supra, p. 35.) Thus, Kaiser could recover
    from ICSOP to the extent that a claim exceeded the $500,000 per
    occurrence limit of the 1974 policy. (Ibid.) “Accordingly, once
    Truck has contributed $500,000 per asbestos bodily injury claim,
    its primary policies are exhausted [with respect to such claim]
    and Truck has no further contractual obligation to Kaiser.” (Ibid.)
    The matter was remanded to the trial court to determine whether
    Kaiser was entitled to summary adjudication of its fifth
    43
    (declaratory relief) and sixth (breach of contract against ICSOP)
    causes of action of the cross-complaint. (Id. at pp. 35–36.)
    ICSOP, however, was only directed to ICSOP’s excess
    obligations and did not discuss whether Truck could allocate
    indemnity among its own policies. (ICSOP, supra at pp. 5–7.) On
    March 28, 2014, Truck filed a Third Amended Complaint, the
    operative complaint for the Phase II trial. Truck alleged it was
    “entitled to allocate amounts paid in indemnity for each
    occurrence among all triggered Truck Policies[.]” Truck asserted
    it could do so based upon the principle that other primary
    insurers at the same level of coverage could seek contribution
    from each other.
    B.    Evidence at Phase II Trial and Statement of
    Decision
    For purposes of the Phase II trial, the parties defined the
    issue as “‘whether Truck, after paying indemnity for an [asbestos
    claim] under its 1974 policy year, can allocate that amount to its
    other policy years that are triggered by the claim.’”
    1.    Evidence At Trial
    The 1971 to 1980 policies contain “anti-stacking”
    provisions. These anti-stacking provisions prevent the insured
    from combining the policy limits of all triggered policies, instead
    limiting the insured to recovery under one policy. All of the
    policies contain an “all sums” insuring agreement as set forth in
    the 1974 policy. The agreement provides that Truck agrees “[t]o
    pay on behalf of the insured all sums which the insured shall
    become obligated to pay” for personal injury damages suffered by
    a third party. While an insurance policy will ordinarily pay “all
    44
    sums” up to its aggregate limit, the 1974 policy had no aggregate
    limit.
    At trial, Kaiser presented evidence showing that under
    Truck’s proposal, Kaiser could potentially lose coverage and
    defense of claims. For example, approximately $4 million
    remained in aggregate coverage under the 1980-1983 primary
    policies; if those policies were exhausted, Kaiser would have to
    seek coverage under excess policies that did not provide a duty to
    defend. Thus, Truck’s proposal could obligate Kaiser to pay some
    portion of defense costs that it otherwise would not be required to
    pay, and could erode the aggregate limits of both the primary and
    excess policies, eventually leaving Kaiser without coverage for
    those years.
    2.    Statement of Decision
    The trial court’s statement of decision discerned two bases
    to deny Truck’s allocation proposal. First, because the other three
    primary insurers’ policies had been exhausted, Truck was the
    only primary insurer still on risk. Thus, Truck’s proposal, “if
    adopted, would allow it to circumvent the ‘all sums’ requirement
    under its policy . . . . it would potentially reduce (or even
    eliminate) coverage for those ‘aggregate year’ policies for future
    [asbestos claims].” Second, the trial court found “Truck’s proposed
    equitable allocation would also contravene the ICSOP ruling. . . .
    ICSOP makes clear that the only available primary insurance for
    a continuing injury [asbestos claim] is the 1974 Truck policy.”
    Truck’s proposed allocation to its other policy years “would, at the
    very least, compromise Kaiser’s right to ‘pick a policy and use it
    up to the policy limits.’ [Citation.]”
    Finally, after observing that California was an “all sums”
    jurisdiction, the trial court concluded Truck’s proposal would blur
    45
    the distinction between “all sums” and “pro-rata” jurisdictions.
    (See Viking Pump, Inc. v. Century Indem. Co. (Del. 2009) 
    2 A.3d 76
     (Viking Pump)). The trial court concluded, “There is not a
    basis under which Truck can equitably contribute benefits under
    the 1974 policy to its other policy years. There are also no cases
    cited by Truck permitting an ‘all sums’ insurer to allocate to its
    own policies in this manner.”
    For the reasons discussed below, we agree with the trial
    court that Truck’s proposal is impermissible, and we affirm the
    Phase II ruling.
    II.   DISCUSSION
    A.    Truck Cannot Apportion Indemnity Across
    Multiple Policies
    Truck asserts that the “all sums” rule does not bar intra-
    insurer contribution. Kaiser, on the other hand, argues that any
    such contribution claim would harm it by reducing or exhausting
    insurance available under the aggregate-limit policies. Excess
    insurers LMI, Fireman’s Fund and Allianz Underwriters
    Insurance Company, who are parties to this phase of the
    litigation, argue that Truck cannot obtain contribution from
    itself.
    1.    Standard of Review
    Truck frames the issue here as one of contribution, an
    equitable principle reviewed for abuse of discretion. The issue,
    however, is the legal question of whether, consistent with the
    insured’s Armstrong election, the insurer may apportion
    indemnity payments across other policies it issued for other
    policy years. If we agree an insurer may do so, how such
    46
    apportionment would be calculated would be an equitable
    question. Whether the insurer may do so in the first place is a
    legal question. (Thompson v. Asimos (2016) 
    6 Cal.App.5th 970
    ,
    985.)
    2.    Truck’s Proposal is Not Equitable
    Contribution
    “Equitable contribution permits reimbursement to the
    insurer that paid on the loss for the excess it paid over its
    proportionate share of the obligation, on the theory that the debt
    it paid was equally and concurrently owed by the other insurers
    and should be shared by them pro-rata in proportion to their
    respective coverage of the risk.” (Fireman’s Fund Ins. Co. v.
    Maryland Casualty Co. (1998) 
    65 Cal.App.4th 1279
    , 1293
    (Fireman’s Fund).) The purpose of the rule “is to accomplish
    substantial justice by equalizing the common burden shared by
    coinsurers, and to prevent one insurer from profiting at the
    expense of others. [Citations.]” (Id. at pp. 1293–1294)
    Equitable contribution is “predicated on the commonsense
    principle that where multiple insurers or indemnitors share
    equal contractual liability for the primary indemnification of a
    loss or the discharge of an obligation, the selection of which
    indemnitor is to bear the loss should not be left to the often
    arbitrary choice of the loss claimant, and no indemnitor should
    have any incentive to avoid paying a just claim in the hope the
    claimant will obtain full payment from another coindemnitor.
    [Citation.]” (Fireman’s Fund, supra, 65 Cal.App.4th at p. 1295.)
    The fact that several insurance policies may cover the same
    risk does not give the insured the right to recover more than
    once. (Fireman’s Fund, supra 65 Cal.App.4th at p. 1295.) “Rather,
    the insured’s right of recovery is restricted to the actual amount
    47
    of the loss. Hence, where there are several policies of insurance
    on the same risk and the insured has recovered the full amount
    of its loss from one or more, but not all, of the insurance carriers,
    the insured has no further rights against the insurers who have
    not contributed to its recovery.” (Ibid.)
    Armstrong addressed contribution rights amongst different
    insurers on the same risk. The court observed that successive
    insurers had the obligation to “‘respond in full’” to the insured’s
    claim, but that obligation was subject to “‘equitable contribution
    from the issuers of other policies triggered by the same claim.’”
    (Armstrong, supra, 45 Cal.App.4th at p. 51.) In discussing
    contribution, Armstrong considered how such contribution
    amongst insurers might be calculated, but did not consider intra-
    insurer contribution. (Id. at pp. 51–52.) Armstrong therefore does
    not support Truck’s proposition that there can be contribution
    between policies issued by the same insurer, nor does any other
    California case.
    Based on these authorities, we conclude Truck’s proposal is
    not a theory of equitable contribution. Truck’s proposal could
    expose Kaiser to detrimental exhaustion of Truck’s policies
    having an aggregate limit, resulting in Kaiser losing coverage for
    what could have been covered claims. Similarly, it could deplete
    or exhaust layers of excess insurance above the other Truck
    policies. Truck does not seek contribution from another insurer
    on the same loss, but rather seeks to shift responsibility for
    payment of future claims from itself to excess carriers or its
    insured.
    Truck responds that its proposal would not necessarily
    erode Kaiser’s coverage because some of those policy years have
    no aggregate limit. Truck stresses that the proposal would allow
    48
    it to access more reinsurance or excess insurance. (See, e.g., St.
    Paul Fire and Marine Ins. Co. v. Ins. Co. (N.D.Cal. Mar. 7, 2017,
    Case No. 15-CV-02744-LHK) 
    2017 U.S. Dist. LEXIS 32551
    , at p.
    31.) Thus, Truck seeks to benefit itself while potentially injuring
    its insured. The proposal therefore is inconsistent with the notion
    of fairness underlying equitable contribution.
    Truck’s resort to the duty of good faith and fair dealing to
    salvage its proposal similarly fails. Truck argues any
    apportionment of damages over its policies is governed by its
    duty of good faith and fair dealing and is subject to judicial
    review. (See, e.g., U.S. Fidelity & Guar. Co. v. American Re-Ins.
    Co. (2013) 
    20 N.Y.3d 407
    , 420 [
    985 N.E.2d 876
    ] (U.S. Fidelity).)
    In U.S. Fidelity, the insurer allocated its losses on no-aggregate
    limit policies to its own advantage and to the disadvantage of its
    reinsurer. (Id. at p. 486.) There, the court adopted a rule of
    “objective reasonableness” to determine good faith allocation, but
    on the facts before it, found no unreasonableness. (Id. at pp. 420–
    421.) Aside from the fact that U.S. Fidelity involved reinsurance
    and has little application here to primary level cross-policy
    allocation, we see no reason to compel Kaiser to engage in after-
    the fact litigation to enforce its rights under the policy through
    the covenant of good faith and fair dealing.
    Nonetheless, Truck contends ICSOP did not consider the
    intra-insurer allocation question because it only considered the
    maximum amount of primary insurance available to pay any one
    claim, a question controlled by the policy language and anti-
    stacking provisions. As a matter of equity, however, Truck
    asserts that issue is distinct from how the amount, once paid, can
    be allocated among policies. Consequently, Truck contends it is
    49
    entitled to allocate losses it pays under one triggered policy to all
    of its triggered policies.
    Contrary to Truck’s assertion, ICSOP does not further its
    argument and does not permit allocating Kaiser’s losses across
    non-1974 triggered policies. ICSOP concluded that based on the
    policies’ anti-stacking provisions, the 1974 policy was the only
    policy available to pay claims triggering that policy. (ICSOP,
    supra, at p. 30.) This holding alone dooms Truck’s argument for
    cross-policy allocation as it is law of the case. The doctrine
    “precludes a party from obtaining appellate review of the same
    issue more than once in a single action.” (Katz v. Los Gatos-
    Saratoga Joint Union High School Dist. (2004) 
    117 Cal.App.4th 47
    , 62; Morohoshi v. Pacific Home (2004) 
    34 Cal.4th 482
    , 491.)
    3.     Truck’s Proposal Violates the All Sums
    Rule of Armstrong
    In contrast to California’s rule of “all sums” is the “pro-
    rata” approach, which “‘assigns a dual purpose to the phrase
    “during the policy period” in the CGL policy’s definition of
    “occurrence.” The phrase serves both as a trigger of coverage and
    as a limitation on the promised “all sums” coverage. . . .’
    [Citation.]” (Continental Insurance, supra, 55 Cal.4th at p. 198.)
    As explained in Continental Insurance, “‘This approach
    emphasizes that part of a long-tail injury will occur outside any
    particular policy period. Rather than requiring any one policy to
    cover the entire long-tail loss, [pro-rata] allocation instead
    attempts to produce equity across time.’ [Citation.]” (Ibid.) As the
    name implies, “[u]nder the most basic scheme of pro-rata
    allocation, an equal share of the amount of damage is assigned to
    each year over which a long-tail injury occurred. The amount
    owed under any one policy is calculated by dividing the number of
    50
    years an insurer was ‘on the risk’ by the total number of years
    that the progressive damage took place. The resulting fraction is
    the portion of the liability owed by the particular insurer.” (Id. at
    p. 199.) Although some states have concluded that pro-rata
    coverage is more equitable, in California the language of CGL
    policies requires that the “all sums” approach is used. (Ibid.)
    As explained in Viking Pump, supra, 
    2 A.3d 76
    , “[t]he all
    sums approach resembles joint and several liability in the sense
    that the insured may collect against any insurer whose policy is
    triggered, up to the policy’s relevant per occurrence total limits,
    in the same way that a plaintiff, if exposed to asbestos by two
    different defendants in the same case, might collect his entire
    judgment from one of the defendants and leave the paying
    defendant to seek contribution from the other defendant in a
    later action. . . . ” (Id. at p. 111, fn. omitted.) Under the pro-rata
    approach, “a court must somewhat arbitrarily divvy up the total
    liability of the insured among its insurers, treating them as if
    they were divisible injuries.” (Id. at p. 112.) If a court “applied the
    so-called ‘time on the risk’ method for prorating liability, the
    court would divide up liability according to what percentage of
    the injury the insurance policy covered.” (Ibid., fn. omitted.)
    “For obvious reasons, the all sums approach tends to be
    favored by insured[s] and the pro-rata approach by insurers. The
    all sums approach lets the insured pick a policy and use it up to
    the policy limits, and leave questions of apportionment to be
    fought out later among the insurers themselves. The pro-rata
    approach gives insurers material reductions in their exposure by
    shifting from the insurer to the insured the risk of periods of
    exposure when the insured lacked coverage or the insurer for
    that period went bankrupt, or during which another defendant
    51
    was responsible for exposure to the insured, even if the insured
    itself was held jointly and severally responsible for the plaintiff’s
    entire harm.” (Viking Pump, supra, 2 A.3d at pp. 112–113.)
    Here, Truck seeks to import the concept of contribution
    among insurers into the “all sums” structure of its own 19
    policies, analogizing its policies to those issued by multiple
    insurers. We find to do so would contravene the “all sums”
    language of the policies requiring Truck to pay all sums due to
    Kaiser, and is inconsistent with Armstrong because it could
    reduce the amount of insurance available to Kaiser and the
    asbestos claimants by exhausting policies with aggregate limits.
    Truck’s proposal runs contrary to its contractual obligation
    to Kaiser to pay “all sums” for which Kaiser is liable. For
    example, asbestos claims with dates of first exposure after 1980
    would trigger only Truck policies with aggregate limits. But those
    policies might be exhausted by Truck’s allocation proposal. As
    explained in Armstrong, “apportionment among multiple insurers
    must be distinguished from apportionment between an insurer
    and its insured. When multiple policies are triggered on a single
    claim, the insurer’s liability is apportioned pursuant to the ‘other
    insurance’ clauses of the policies [citations] or under the
    equitable doctrine of contribution. [Citations.] That
    apportionment [among insurers], however, has no bearing upon
    the insurer’s obligation to the policyholder [Citation.] . . . .
    [Citation.] The insurers’ contractual obligation to the policyholder
    is to cover the full extent of the policyholder’s liability (up to the
    policy limits).” (Armstrong, supra, 45 Cal.App.4th at pp. 105–
    106.) In other words, the insurer must pay “all sums” under the
    policy, rendering equitable contribution a matter between
    insurers, unrelated to the insurer’s contractual indemnity
    52
    obligation to its insured. (Aerojet, 
    supra,
     17 Cal.4th at p. 72
    [equitable contribution “has no place between insurer and
    insured”]; Dart Industries Inc. v. Commercial Union Ins. Co.
    (2002) 
    28 Cal.4th 1059
    , 1080.)
    Truck’s proposal would be detrimental to Kaiser because it
    could exhaust policies available to Kaiser for claims that do not
    trigger the 1974 policy. Truck could exhaust those non-1974
    policies that have aggregate limits with its proposal, leaving
    Kaiser with no indemnification for future claims that trigger
    those policies but not the 1974 policy. As explained in Flintkote
    Co. v. General Accident Assur. Co. (N.D.Cal. Aug. 6, 2008, No.
    C 04-01827 MHP) 
    2008 U.S. Dist. LEXIS 108245
     (Flintkote),
    upon which Truck relies, “where an insurer with unlimited
    aggregate liability breaches, and the gap is filled by an insurer
    whose performance [erodes] a liability policy with an aggregate
    limit, the insured suffers damage directly when the policy with
    an aggregate limit is unavailable to respond to later claims. In
    other words, [the insured] is directly harmed insofar as it can no
    longer rely on the policy with an aggregate limit to cover future
    claims and is forced to pay the claim on its own.” (Id. at pp. 10–
    11.)11
    11     Generally, an unpublished California opinion may not be
    cited or relied upon. (Cal. Rules of Court, rule 8.1115.) However,
    citation to unpublished opinions from other jurisdictions for their
    persuasive value does not violate this rule. (See Farm Raised
    Salmon Cases (2008) 
    42 Cal.4th 1077
    , 1096, fn. 18, emphasis
    omitted [“Citing unpublished federal opinions does not violate our
    rules [Citation.]”].) Opinions from other jurisdictions—some of
    which have different publication criteria than California—can be
    cited without regard to their publication status and may be
    53
    Truck posits that the only difference between all-sums and
    pro-rata jurisdictions is when the allocation is made—after a
    claim is handled, even under an all-sums approach the loss may
    be equitably distributed between all triggered policies because
    even Armstrong recognized the “‘method of allocation only affects
    the timing of payments.’” (Armstrong, supra, 45 Cal.App.4th at p.
    53, fn. 17.) We disagree. Truck’s cited portion of Armstrong’s
    allocation discussion did not discuss intra-insurer allocation, but
    instead related to equitable contribution among insurers on the
    same risk. (Id. at p. 53.) On that basis, it is of no help to Truck.
    Thus, we reject Truck’s attempt to escape the confines of
    the Armstrong rule by arguing it can obtain contribution from
    itself via allocation of losses under the 1974 policy to other policy
    years. Armstrong observed that although the all-sums approach
    prevents an insurer from apportioning a share of the loss to the
    insured, the insurers can apportion a loss among themselves as
    long as at least one of them makes good on all sums owed to the
    insured. (Armstrong, supra, 45 Cal.App.4th at p. 51.) This rule
    does not mean Truck can obtain contribution from itself—Truck’s
    self-contribution theory does not equate to contribution among
    different insurers. (Ibid.; see also, Flintkote, supra, 2008
    U.S.Dist. LEXIS 108245 pp. 17–21.)
    regarded as persuasive. (Central Laborers’ Pension Fund v.
    McAfee, Inc. (2017) 
    17 Cal.App.5th 292
    , 319, fn. 9.) In that
    regard, unpublished federal opinions are citable as persuasive,
    although not precedential, authority. (Pacific Shore Funding v.
    Lozo (2006) 
    138 Cal.App.4th 1342
    , 1352, fn. 6.)
    54
    PHASE III-A: (1) DUTY OF EXCESS CARRIERS TO DROP
    DOWN AND (2) AMOUNT OF TRUCK’S PER
    OCCURRENCE INDEMNITY OBLIGATION UNDER THE
    1974 POLICY
    The Phase III-A trial addressed two issues. The first issue
    was “[w]hether the first layer excess/umbrella policies of [LMI,
    First State, and Westchester Fire Insurance] ha[d] a duty to ‘drop
    down’ and contribute a pro-rata share for their policy years to
    Truck.”12 The trial court said no. We agree. The second issue was
    whether Truck has a “contractual obligation to pay a [per
    occurrence] limit of liability up to $500,000 or $495,000 under the
    terms of its 1974 primary policy.” The trial judge ruled that
    Truck was obligated to pay up to $495,000 in indemnity
    payments, with Kaiser contributing $5,000 as a deductible. We
    agree with that ruling as well.
    Phase III-A, Part 1
    I.    EVIDENCE AT PHASE III-A, PART 1 TRIAL
    Truck argued that because the other three primary
    insurers’ policies had been exhausted, pursuant to the “other
    insurance” clause in its own policies, as well as the excess
    policies’ language requiring them to “drop down,” the excess
    12     Previously, in ICSOP, the court held that ICSOP’s excess
    policy attached when a claim exhausted the $500,000 per claim
    limit. (ICSOP, supra, at p. 56.) Thus, the ICSOP policy was not at
    issue in Phase III-A, part 1. (See, e.g., Trial Court’s Statement of
    Decision, Phase III-A, p. 38, fn. 21.)
    55
    insurers13 were required to defend and indemnify Kaiser
    “immediately upon the exhaustion of the aggregate limits of
    liability of the primary policy directly beneath” them.
    A.    Excess Policy Provisions
    The excess policies14 contained the following relevant
    provisions:
    LMI: The LMI policies were in effect from 1947 to 1964,
    and stated that they would attach upon exhaustion of “other
    13    Excess insurers LMI, Westchester and First State filed
    separate respondents’ briefs in Truck’s Phase III-A appeal.
    Joining in LMI’s respondent’s brief are excess insurers ICSOP,
    Granite State Insurance Company, Continental Insurance
    Company, Fireman’s Fund Insurance Company, Allianz
    Underwriters Insurance Company, National Casualty Company,
    Sentry Insurance, Evanston Insurance Company, Transport
    Insurance Company, and TIG Insurance Company. Joining in
    First State’s respondent’s brief are excess insurers Evanston
    Insurance Company and TIG Insurance Company. Joining in
    Westchester’s respondent’s brief are excess insurers Transport
    Insurance Company, Granite State Insurance Company,
    Evanston Insurance Company and TIG Insurance Company.
    14    Excess insurance policies have several forms. An excess
    policy may be written as (1) excess to a particular policy or
    policies; (2) excess to coverage provided by a particular primary
    insurer; (3) excess to any insurance coverage available to the
    insured; or (4) excess to the applicable limits of scheduled
    policies. (Croskey et al., Cal. Practice Guide: Insurance
    Litigation (The Rutter Group 2021) ¶ 8:181 (Rutter Guide).)
    Where the excess is excess to identified policies, it is called
    “specific excess.” (Olympic Insurance. v. Employers Surplus Lines
    Ins. Co. (1981) 
    126 Cal.App.3d 593
    , 598 (Olympic Insurance).)
    56
    insurances . . . whether recoverable or not . . .” The 1958 to 1961
    policies provided if other valid and collectible insurance with
    another insurer was available to the insured covering a loss also
    covered by LMI, other than LMI’s excess insurance, “the
    insurance afforded by this certificate shall be in excess of and
    shall not contribute with such other insurance.” The 1961 to 1964
    policies stated that the policies were excess of the limits of the
    underling insurance, and specified that “[i]f other valid and
    collectible insurance with any other insurer is available to the
    Assured covering a loss also covered by this policy, other than
    insurance that is in excess of the insurance afforded by this
    policy, the insurance afforded by this policy shall be in excess of
    and shall not contribute with other insurance.”
    Westchester: The Westchester policy was in effect from
    May 1, 1984 to April 1, 1985. The policy provided that “the
    company’s liability shall be only for the ultimate net loss in
    excess of the insured’s retained limit defined as the greater of:
    [¶] the total of the applicable limits of the underlying policies
    listed in Schedule A hereof, and the applicable limits of any other
    insurance collectible by the insured . . .” (Emphasis added.) The
    policy also provided that in the event of reduction or exhaustion
    of the underlying policies listed on Schedule A, the Westchester
    policy “shall continue in force as underlying insurance.”
    First State: First State’s excess policy was issued for the
    1983 to 1984 policy year. First State promised to indemnify “an
    amount equal to the limits of liability indicated beside the
    underlying insurance listed in the Schedule A of underlying
    insurance, plus the applicable limits of any other underlying
    insurance collectible by the insured[.]” (Emphasis added.)
    57
    B.   Statement of Decision
    The trial court found the excess insurers had no duty to
    “drop down” and equitably contribute to Truck under the 1974
    policy, rejecting Truck’s argument there had been “vertical
    exhaustion” of the other primary insurers’ policies. Instead, the
    trial court found that the default California rule of “horizontal
    exhaustion” controlled, as set forth in Community Redevelopment
    Agency v. Aetna Casualty & Surety Co. (1996) 
    50 Cal.App.4th 329
    (Community Redevelopment). Under that rule, all primary
    insurance must exhaust before any excess policy must indemnify
    the insured. (Id. at p. 339.) Horizontal exhaustion is contrasted
    with “vertical exhaustion,” where “coverage attaches under an
    excess policy when the limits of a specifically scheduled
    underlying policy are exhausted and the language of the excess
    policy provides that it shall be excess only to that specific
    underlying policy.” (Id. at pp. 339–340, fn. omitted.)
    The trial court concluded that Community Redevelopment
    and ICSOP controlled, having addressed identical excess policy
    language, and as a result the excess carriers had no duty to drop
    down until there was horizontal exhaustion, namely, all primary
    policies on the risk exhausted. The court explained that
    Community Redevelopment made it clear that in spite of a
    reference to scheduled underlying insurance, where the excess
    policy contained the phrase “other insurance,” the rule of
    horizontal exhaustion applied, and that Truck’s interpretation
    would convert excess insurers into primary insurers.
    II.   DISCUSSION
    Truck argues that the 1974 no-aggregate limit primary
    policy can trigger the excess insurers to drop down on a per
    58
    occurrence basis, rather than when all primary insurance has
    been exhausted, thereby converting the excess policies into
    policies that vertically exhaust by virtue of being “specific
    excess.”
    Truck reaches this result by selectively focusing on the
    “continue in force as underlying insurance” language providing
    the excess policies attach upon exhaustion of specifically
    scheduled underlying primary policies, thereby transforming the
    policies into “specific excess” policies that need not horizontally
    exhaust. Truck asserts it therefore falls within the exception to
    the horizontal exhaustion rule set forth in Community
    Redevelopment for policies “describing and limiting the
    underlying insurance” as the policy language in both instances is
    basically equivalent. (See Community Redevelopment, supra, 50
    Cal.App.4th at p. 340, emphasis omitted.) In addition, Truck
    argues that the recent decision of Montrose III, supra, 
    9 Cal.5th 215
     supports its position because Montrose III has essentially
    eliminated horizontal exhaustion where, as here, a specific
    underlying primary insurance has exhausted. We disagree,
    finding Community Redevelopment controls and as a result, all
    primary policies must exhaust.
    A.    Standard of Review
    “Normal rules of policy interpretation [ ] apply in
    determining coverage under excess policies.” (Croskey et al., Cal.
    Practice Guide: Insurance Litigation (The Rutter Group 2020)
    ¶ 8:180.) “While insurance contracts have special features, they
    are still contracts to which the ordinary rules of contractual
    interpretation apply. [Citations.]” (Foster-Gardner, Inc. v.
    National Union Fire Ins. Co. (1998) 
    18 Cal.4th 857
    , 868.) While
    the primary policy may be consulted in interpreting an excess
    59
    policy, each policy is a separate document and is interpreted
    separately. (Croskey et al., Cal. Practice Guide: Insurance
    Litigation, supra, ¶ 8:180.5; Northrop Grumman Corp. v. Factory
    Mut. Ins. Co. (9th Cir. 2009) 
    563 F.3d 777
    , 785 [primary policy
    must be consulted in interpreting the excess policy, but court
    does not treat the two documents as one contract].) Where, as
    here, there are no factual disputes and hence the interpretation
    of the contracts does not depend upon extrinsic evidence, their
    interpretation is a matter of law. (Oh v. Teachers Ins. and
    Annuity Assn. of America (2020) 
    53 Cal.App.5th 71
    , 84.)
    B.    Excess and Primary Insurance
    Primary insurance, or the first layer of insurance, provides
    immediate coverage upon the occurrence of a loss. (St. Paul
    Mercury Ins. Co. v. Frontier Pacific Ins. Co. (2003) 
    111 Cal.App.4th 1234
    , 1252-1253.) Excess insurance, or the second
    (or higher) layer of insurance, provides coverage once primary
    insurance is exhausted. (Montrose III, supra, 9 Cal.5th at p. 222.)
    “An excess insurer’s obligation begins once a certain level of loss
    or liability is reached; that level is generally referred to as the
    ‘“attachment point”‘ of the excess policy. [Citation.]” (Id. at p.
    223.) As long as primary coverage exists, an excess insurer has no
    duty to contribute to defense or indemnity. (Olympic Insurance,
    supra, 126 Cal.App.3d at p. 601.) No contractual obligations exist
    between primary and excess insurers; rather any rights and
    duties flow from equitable principles. (Signal Cos. v. Harbor Ins.
    Co. (1980) 
    27 Cal.3d 359
    , 369.)
    60
    C.    Community Redevelopment and Horizontal
    Exhaustion
    Community Redevelopment applied the default “horizontal
    exhaustion” rule in holding that an excess insurer had no duty to
    drop down and provide a defense to an insured before the liability
    limits of all primary policies had been exhausted. (Community
    Redevelopment, supra, 50 Cal.App.4th at p. 341.) There, the
    “unambiguous” excess policy language conditioned coverage on
    the exhaustion of “‘any . . . valid and collectible’” underlying
    insurance, which language Community Redevelopment held must
    be read to include all available primary insurance. (Id. at pp.
    338–339.) Community Redevelopment reasoned that applying the
    horizontal exhaustion rule to continuous loss cases remained
    consistent with Montrose I, which holds that long-tail losses are
    covered by all policies in effect during the periods of injury.
    (Montrose I, supra, 10 Cal.4th at p. 673.) “Absent a provision in
    the excess policy specifically describing and limiting the
    underlying insurance, a horizontal exhaustion rule should be
    applied in continuous loss cases . . . [A]ll of the primary policies
    in force during the period of continuous loss will be deemed
    primary policies to each of the excess policies covering that same
    period. . . . [Thus,] all of the primary policies must exhaust[.]”
    (Community Redevelopment, supra, 50 Cal.App.4th at p. 340; see
    also Stonewall Ins. Co. v. City of Palos Verdes Estates (1996) 
    46 Cal.App.4th 1810
    , 1853 (Stonewall) [horizontal exhaustion
    approach more consistent with Montrose’s continuous trigger
    approach].) As Stonewall further explained, “if ‘occurrences’ are
    continuously occurring throughout a period of time, all of the
    primary policies in force during that period of time cover these
    occurrences, and all of them are primary to each of the excess
    61
    policies; and if the limits of liability of each of these primary
    policies is adequate in the aggregate to cover the liability of the
    insured, there is no ‘excess’ loss for the excess policies to cover.”
    (Stonewall, supra, 46 Cal.App.4th at p. 1853.)
    D.     Montrose III and Vertical Exhaustion
    Community Redevelopment considered an underlying layer
    of primary insurance. In contrast, Montrose III considered
    multiple layers of excess insurance. (Montrose III, supra,
    9 Cal.5th at p. 226.) Montrose III held that based on policy
    language equivalent to that analyzed in Community
    Redevelopment, a vertical exhaustion rule applied. (Id. at pp. 226,
    237.) Addressing the order in which an insured may access excess
    policies from different policy periods to cover liability arising
    from long-tail injuries, the insurers argued that the “other
    insurance” clauses in the excess policies providing “that each
    policy shall be excess to other insurance available to the insured,
    whether or not the other insurance is specifically listed in the
    policy’s schedule of underlying insurance” mandated horizontal
    exhaustion. (Id. at p. 230.) Thus, they reasoned, in the case of a
    long-tail injury, “every policy with a lower attachment point from
    every policy period triggered by the continuous injury” must
    exhaust before a higher-level excess policy must contribute.
    (Ibid.)
    Rejecting the insurers’ arguments, Montrose III applied a
    rule of vertical exhaustion and concluded “that in a case involving
    continuous injury, where all primary insurance has been
    exhausted, the policy language at issue” permitted “the insured
    to access any excess policy for indemnification during a triggered
    policy period once the directly underlying excess insurance has
    62
    been exhausted.” (Montrose III, supra, 9 Cal.5th at p. 237.)
    Montrose III relied on both the policy language regarding “other
    insurance” as well as the practicalities and equities of multiple
    layers of excess insurance and long-tail injuries. (Ibid.)
    Examining the policy language, Montrose III first observed
    that the “other insurance clauses” did not “speak clearly to the
    question before” it. (Montrose III, supra, 9 Cal.5th at p. 233.)
    Instead, “other aspects of the insurance policies strongly suggest
    that the exhaustion requirements were meant to apply to directly
    underlying insurance and not to insurance purchased for other
    policy periods.” (Ibid.) Montrose III found that “other insurance”
    clauses were traditionally used to prevent multiple recoveries
    when more than one policy provided coverage for a particular
    loss, and they “have not generally been understood as dictating a
    particular exhaustion rule for policy holders seeking to access
    successive [layers of] excess insurance policies in cases of long-
    tail injury.” (Id. at p. 231.) Rather, such clauses “have generally
    been used to address ‘[a]llocation questions with respect to
    overlapping concurrent policies.’ [Citation.]” (Id. at p. 232,
    emphasis in original.)
    Montrose III relied on the policies’ express statement of
    their attachment point, “generally by referencing a specific dollar
    amount of underlying insurance in the same policy period that
    must be exhausted.” (Montrose III, supra, 9 Cal.5th at p. 233.)
    Further, the excess policies included or referenced schedules of
    underlying insurance, all covering the same policy period. (Id. at
    p. 234.) Montrose III rejected the insurers’ interpretation and
    concluded that “[r]ather, in the absence of any more persuasive
    indication that the parties intended otherwise, the policies are
    most naturally read to mean that [the insured] may access its
    63
    excess insurance whenever it has exhausted the other directly
    underlying excess insurance policies that were purchased for the
    same policy period.” (Ibid.)
    Applying an additional rationale, Montrose III found
    myriad “practical obstacles to securing indemnification” that
    precluded horizontal exhaustion, namely, the lack of
    standardization of policy language that would require
    examination of myriad different periods of time, differing levels of
    coverage, and distinct exclusions, terms, and conditions.
    (Montrose III, supra, 9 Cal.5th at p. 235.) “In sum, ‘[h]orizontal
    exhaustion would create as many layers of additional litigation as
    there are layers of policies.’ [Citation.]” (Ibid.) “A rule of vertical
    exhaustion does not restrict the insured from accessing excess
    coverage from other [excess] policy periods if the terms and
    conditions are otherwise met; it merely relieves the insured of the
    obligation of establishing whether all of the applicable terms and
    conditions at any given ‘layer’ of excess coverage are met before it
    accesses the next ‘layer’ of coverage.” (Id. at pp. 235–236.)
    Finally, Montrose III distinguished Community
    Redevelopment, supra, 
    50 Cal.App.4th 329
    . (Montrose III, supra,
    9 Cal.5th. at p. 237.) Montrose III noted that the procedural
    posture of the case before it was different than Community
    Redevelopment: Montrose III involved a dispute between an
    insured and its excess insurers, while Community Development,
    like the case before us, involved a dispute between a primary
    insurer and an excess insurer. (Montrose III, supra, 9 Cal.5th. at
    p. 237.)
    In spite of Montrose III’s directive with respect to primary
    insurance, a recent case applied Montrose III to primary
    insurance. In SantaFe Braun, Inc. v. Insurance Co. of North
    64
    America (2020) 
    52 Cal.App.5th 19
     (SantaFe Braun), the appellate
    court extended Montrose III and concluded that primary
    insurance need not be horizontally exhausted across all policy
    years before excess coverage in a particular policy year is
    triggered. (Id. at p. 29.) SantaFe Braun reasoned that the first-
    level excess policies contained language comparable to that in
    Montrose III, suggesting that the exhaustion requirements
    applied to directly underlying insurance and not to insurance
    purchased for other policy periods. (Id. at p. 28.) Thus, any
    differences between primary and excess insurance “provide[d]
    little justification for construing the policy language interpreted
    in Montrose III differently simply because primary coverage
    purchased often many years later for other policy periods
    remain[ed] outstanding.” (Ibid.)
    SantaFe Braun found the difference in premiums paid
    similarly provided no justification for distinguishing between
    multiple levels of excess insurance on the one hand and primary
    and excess insurance on the other. (SantaFe Braun, supra, 52
    Cal.App.5th at pp. 28–29.) “If horizontal exhaustion of all
    primary insurance were required to trigger the coverage, the
    level of liability at which the excess coverage would attach would
    be unascertainable. . . . The difference between premiums paid
    for excess and for primary policies does not justify an
    interpretation that renders the point of attachment so
    unpredictable and unascertainable when the policy is issued.”
    (Ibid.) Finally, the differing defense obligations of primary and
    excess insurers did not compel horizontal exhaustion because the
    rule that an excess insurer has no duty to defend absent policy
    language to the contrary would apply whether horizontal or
    vertical exhaustion was applied. (Id. at p. 29.) In conclusion,
    65
    SantaFe Braun found Community Redevelopment’s horizontal
    exhaustion rule did not apply because it relied on an
    interpretation of the policy language rejected by Montrose III. (Id.
    at p. 30.)
    E.    All Primary Insurance Must Exhaust
    We disagree with SantaFe Braun that there is no
    distinction between multiple layers of excess insurance, as in
    Montrose III, and layers of primary and excess insurance. One of
    the rationales of Montrose III—that it was too difficult to
    determine attachment points when multiple layers of excess
    insurance were implicated—does not apply here, where there is
    only one underlying layer of insurance, namely, primary
    insurance and it is easy to ascertain whether that insurance has
    been exhausted.
    Second, primary and excess insurance are qualitatively
    different. Primary policies attach as first-dollar coverage and
    have an immediate obligation to respond; primary policies have
    the right to control the defense without input from excess
    insurers; and primary policies generally do not use defense costs
    to reduce limits. (See, e.g., Columbia Casualty. Co. v. Northwest
    Nat. Ins. Co. (1991) 
    231 Cal.App.3d 457
    , 470–472.) Significantly,
    the premiums charged for primary insurance differ from excess
    insurance because the latter insurance may never be called upon
    to indemnify the insured, whereas primary insurance is always
    implicated if a claim is filed. (See, e.g., Padilla Construction Co.,
    Inc. v. Transportation Ins. Co. (2007) 
    150 Cal.App.4th 984
    , 1003.)
    We therefore apply Community Redevelopment to the
    language in the excess insurers’ policies, and find horizontal
    exhaustion applies. Such policies all have language tracking the
    horizontal exhaustion language examined in Community
    66
    Redevelopment and in ICSOP. Both the Westchester and First
    State policies expressly refer to “other insurance” or “other
    underlying insurance” that must exhaust. The policies in LMI
    have different language that expresses the same concept: “after
    making deductions for all recoveries, salvages, and other
    insurances[,]” “if other valid and collectible insurance with
    another insurer was available to the insured covering a loss also
    covered by LMI, other than LMI’s excess insurance, the
    insurance afforded by this certificate shall be in excess of and
    shall not contribute with such other insurance[,]” and that “[i]f
    other valid and collectible insurance with any other insurer is
    available to the Assured covering a loss also covered by this policy,
    other than insurance that is in excess of the insurance afforded
    by this policy, the insurance afforded by this policy shall be in
    excess of and shall not contribute with other insurance.”
    In spite of the clear directive of the horizontal exhaustion
    rule, Truck argues the 1974 no-aggregate limit primary policy
    can still trigger excess drop-down on a per occurrence basis,
    converting the excess policies into policies that vertically exhaust
    by virtue of being “specific excess.” Truck does so by selectively
    focusing on the “continue in force as underlying insurance”
    language that applies upon exhaustion of specifically scheduled
    underlying primary policies. Truck takes this language out of
    context and reads it in isolation from the rest of the policy,
    however. The “continue in force” language is modified not only by
    the specified underlying policies, but also by the “other
    insurance” that also must be exhausted. Indeed, the key language
    is the “other insurance” language of the policies, which requires
    horizontal exhaustion.
    67
    F.    No Contribution From Excess Insurers
    To the extent Truck separately argues for contribution from
    the excess insurers, we are unpersuaded.
    Insurers can obtain contribution from other insurers on the
    same risk and sharing the same level of liability (North American
    Capacity Ins. Co. v. Claremont Liability Ins. Co. (2009) 
    177 Cal.App.4th 272
    , 295.) Absent a specific agreement to the
    contrary, there is no contribution between primary and excess
    insurers. (Reliance Nat. Indemnity Co. v. General Star Indemnity
    Co. (1999) 
    72 Cal.App.4th 1063
    , 1080.)
    Here, Truck’s argument necessarily assumes its own
    erroneous conclusion: that the excess policies have already
    dropped down and thus contribution is appropriate between
    insurers because they are now on the same level. The reality is
    that Truck, as a primary insurer, cannot obtain contribution from
    an insurer on a different level.
    Phase III-A, Part 2
    Truck and the excess insurers disputed the meaning and
    effect of the deductible provision in the 1974 policy. The trial
    court agreed with Truck that the deductible reduced the total
    $500,000 limit available under the 1974 policy such that
    $495,000 was recoverable. The excess insurers argued that the
    $5,000 deductible reduces covered damages, and did not reduce
    Truck’s $500,000 per occurrence limit because the policy
    language does not contain the “difference between” language that
    is the hallmark of deductibles that reduce limits. LMI and ICSOP
    cross-appeal the trial court’s ruling on the deductible issue.
    68
    A.    Factual Background
    The 1974 policy has a per occurrence limit of $500,000. The
    policy states that “$5,000 shall be deducted from the total
    amount to be paid for all damages which the Insured becomes
    legally obligated to pay on account of each occurrence.”
    At trial, Truck asserted this language meant its policy limit
    was effectively reduced to $495,000 for each occurrence.
    Meanwhile the excess insurers asserted that the deductible
    would first be applied to the claim, followed by Truck’s full
    $500,000 limit, before the claim could be submitted to the excess
    insurers. The excess insurers introduced extrinsic evidence
    regarding the parties’ course of performance, citing two examples
    to establish that Truck acknowledged its obligations to pay the
    full $500,000: In the first, the “Kiln Brick incident” of 1983,
    Truck treated Kaiser’s deductible as coming out of the “total
    amount to be paid for all damages[.]” The second example arose
    from the current litigation, where Kaiser acknowledged that the
    $5,000 per occurrence deductible was to be deducted not from the
    policy limit but from the total amount of each asbestos
    settlement.
    The trial court framed the issue as “[w]hether Truck has a
    contractual obligation to pay a limit of liability up to $500,000 or
    $495,000 under the terms of its 1974 primary policy[.]” Relying
    on an analysis of comparable policy language in the Rutter Guide
    at ¶¶ 7:380 et seq., the court considered whether the deductible
    language had the effect of making the insured responsible for the
    first $5,000 of damages, or whether it had the effect of reducing
    policy coverage. The trial court concluded the policy language
    stating “the ‘total amount to be paid for all damages which [the
    Insured] becomes legally obligated to pay on account of each
    69
    occurrence’ “meant the deductible of the 1974 policy was of the
    type that reduced coverage. The trial court observed that “[t]o
    adopt the Excess Carriers’ interpretation would, for all intents
    and purposes, eliminate the deductible provision, because Truck’s
    limit of liability would be increased to $505,000 (and not the
    $500,000 set forth in the Truck policy).”
    B.    The $5,000 Deductible of the 1974 Policy
    Reduces Policy Limits
    1.     Standard of Review and Principles of
    Contract Interpretation
    “The interpretation of a contract is a judicial function.
    [Citation.] . . . . Ordinarily, the objective intent of the contracting
    parties is a legal question determined solely by reference to the
    contract’s terms. [Citations.]” (Wolf v. Walt Disney Pictures and
    Television (2008) 
    162 Cal.App.4th 1107
    , 1125–1126.) While the
    court generally may not consider extrinsic evidence to interpret a
    contract, such evidence is admissible to interpret an agreement
    when a material term is ambiguous. (Id. at p. 1126) The terms of
    a writing can “be explained or supplemented by course of dealing
    or usage of trade or by course of performance.” (Code Civ. Proc.,
    § 1856, subd. (c).) “Indeed, where there is a fixed and established
    usage and custom of trade, the parties are presumed to contract
    pursuant thereto. [Citations.] Thus, courts can rely on usage and
    custom to imply a term where the contract itself is silent in that
    regard.” (Southern Pacific Transportation Co. v. Santa Fe Pacific
    Pipelines, Inc. (1999) 
    74 Cal.App.4th 1232
    , 1240–1241.) “An
    appellate court is not bound by a trial court’s construction of a
    contract where . . . there is no conflict in the properly admitted
    extrinsic evidence . . . . [H]owever, where the interpretation of the
    70
    contract turns upon the credibility of conflicting extrinsic
    evidence which was properly admitted at trial, an appellate court
    will uphold any reasonable construction of the contract by the
    trial court. [Citation.]” (Morey v. Vannucci (1998) 
    64 Cal.App.4th 904
    , 913.) Here, the parties admitted evidence of their custom
    and practice with respect to the deductible, but the trial court
    ruled on the issue by solely addressing the policy language,
    thereby implicitly finding the language to be unambiguous. We
    make the same finding.
    2.    The Deductible Language Has the Effect of
    Reducing Policy Limits
    “‘Liability insurance policies often contain a “deductible” or
    a “self-insured retention” (SIR) requiring the insured to bear a
    portion of a loss otherwise covered by the policy.’ [Citation.]”
    (Forecast Homes, Inc. v. Steadfast Ins. Co. (2010) 
    181 Cal.App.4th 1466
    , 1473-1474; see also Deere & Co. v. Allstate Ins. Co. (2019)
    
    32 Cal.App.5th 499
    , 505 [discussing different effect of SIRs and
    deductibles on policy limits in context of whether primary policy
    SIRs are incorporated into excess policies].) The amount of the
    deductible is ordinarily set forth on the declarations page or in an
    endorsement to the policy. (Croskey et al., Cal. Practice Guide:
    Insurance Litigation, supra, ¶ 7:379.)
    In explaining the types of deductibles, the Rutter Guide
    gives two examples. The first is where the deductible is “per
    occurrence,” under which the insured is responsible for the first
    deductible portion of damages, but the policy limits remain the
    same. (Croskey et al., Cal. Practice Guide: Insurance Litigation,
    supra, ¶¶ 7.380, 7.380.1.) Such language is often styled, “[t]he
    $10,000 Deductible stated in the Declarations shall be applicable
    71
    to each occurrence. [Citation.]” (Id. at ¶ 7.380.1.) In practical
    effect, “[t]he insured is responsible for the first $10,000 of
    damages, but the policy limits are not affected. . . . [T]he insurer
    is responsible for all damages exceeding $10,000 up to the full
    policy limits, as well as for defense costs.” (Id. at ¶ 7:380.2.)
    A second example involves a deductible that can effectively
    reduce coverage. Such a deductible may be described as “The
    $10,000 Deductible stated in the Declarations shall be applicable
    to each occurrence and the Company shall be liable only for the
    difference between such deductible amount and the amount of
    insurance otherwise applicable to each claim.” (Croskey et al.,
    Cal. Practice Guide: Insurance Litigation, supra, ¶ 7380.5,
    emphasis added.) This language would result in the first $10,000
    of damages being paid by the insured. (Id at. ¶ 7380.6.) “The
    amount paid by [the insured] reduces the amount of coverage
    otherwise available; i.e., the policy limits are reduced by
    $10,000.” (Ibid.)
    Here, the trial court did not err. We need not consider the
    extrinsic evidence of custom and practice because the language of
    the policy is not ambiguous. Although the language does not
    precisely track the Rutter Guide examples, those examples are
    instructive. The deductible language here is more like the second
    Rutter Guide example because it relates to the difference
    between the deductible and the policy limits. It therefore has the
    effect of reducing coverage because it states “$5,000 shall be
    deducted from the total amount to be paid for all damages which
    the Insured becomes legally obligated to pay on account of each
    occurrence.” (Emphasis added.) This unambiguous language has
    the net effect of reducing the policy limits by the amount of the
    deductible.
    72
    DISPOSITION
    The portion of the final judgment relating to Phase I is
    reversed. Deductibles on claims where any indemnity payment
    was made more than four years before the filing of Truck’s second
    amended complaint on August 23, 2007 are time-barred and may
    not be reopened. The matter is remanded to the trial court for
    further proceedings consistent with our Phase I holding.
    The judgment with respect to Phase II is affirmed. The
    judgment with respect to Phase III-A, Part One and Phase III-A,
    Part Two, is also affirmed.
    Kaiser shall recover its costs on appeal from Truck. All
    other parties shall bear their own costs.
    NOT TO BE PUBLISHED IN THE OFFICIAL REPORTS
    CURREY, J.
    We concur:
    WILLHITE, Acting P.J.
    COLLINS, J.
    73