Waters v. Day & Zimmermann NPS, Inc. ( 2022 )


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  •           United States Court of Appeals
    For the First Circuit
    No. 20-1997
    JOHN WATERS,
    individually and for others similarly situated,
    Plaintiff, Appellee,
    v.
    DAY & ZIMMERMANN NPS, INC.
    Defendant, Appellant.
    APPEAL FROM THE UNITED STATES DISTRICT COURT
    FOR THE DISTRICT OF MASSACHUSETTS
    [Hon. Nathaniel M. Gorton, U.S. District Judge]
    Before
    Thompson, Dyk,* and Barron,
    Circuit Judges.
    David B. Salmons, with whom Michael J. Puma, James D. Nelson,
    and Morgan, Lewis & Bockius LLP were on brief, for appellant.
    Richard J. (Rex) Burch, with whom Michael A. Josephson,
    Richard M. Schreiber, Taylor A. Jones, Bruckner Burch PLLC, and
    Josephson Dunlap LLP were on brief, for appellee.
    Daryl Joseffer, Jonathan D. Urick, Nicole A. Saharsky, Andrew
    J. Pincus, Archis A. Parasharami, Minh Nguyen-Dang, and Mayer Brown
    LLP on brief for Chamber of Commerce of the United States of
    America, amicus curiae.
    * Of the United States Court of Appeals for the Federal
    Circuit, sitting by designation.
    January 13, 2022
    DYK, Circuit Judge.    John Waters filed suit for overtime
    wages   pursuant   to   § 216(b)   of    the   Fair   Labor   Standards   Act
    ("FLSA"), 
    29 U.S.C. §§ 201
    –219, in the United States District Court
    for the District of Massachusetts.             The defendant was Day &
    Zimmermann   ("D&Z"),    a    company    incorporated    in   Delaware    that
    maintains its principal place of business in Pennsylvania.
    Waters's suit alleged that D&Z failed to pay him and
    other similarly situated employees and former employees their
    FLSA-required overtime wages. In accord with the FLSA's procedures
    governing what are often referred to as "collective actions," more
    than 100 current and former D&Z employees from around the country
    filed "opt-in" consent forms with the district court electing to
    participate as plaintiffs in Waters' suit.
    D&Z moved to dismiss for lack of personal jurisdiction.
    This motion was based on Bristol-Myers Squibb v. Superior Court of
    California ("BMS"), 
    137 S. Ct. 1773
    , 1779, 1781 (2017), holding
    that in view of the Fourteenth Amendment, state courts cannot
    entertain a state-law mass action—an aggregation of individual
    actions—if it includes out-of-state plaintiffs with no connection
    to the forum state.      Here, the claims subject to the motion to
    dismiss were the claims of the current and former D&Z employees
    who had opted in to the collective action but, who, unlike Waters,
    had     worked   for    the    company     outside      of    Massachusetts.
    Notwithstanding that D&Z had been properly served with process, it
    - 3 -
    claimed that under BMS, these claims could not be brought in a
    Massachusetts         federal      court,    even    though   a   federal       court's
    jurisdiction is determined by the Fifth Amendment Due Process
    Clause.       This is so, D&Z argued, because Federal Rule of Civil
    Procedure         ("FRCP"     or   "Rule")   4(k)(1)    independently          limits   a
    federal court's exercise of personal jurisdiction with respect to
    out-of-state opt-in claimants added after service of process has
    been       effectuated.        The   district       court   denied     D&Z's    motion,
    declining to extend BMS's personal jurisdiction requirements to
    FLSA cases in federal court.            Waters v. Day & Zimmermann NPS, Inc.,
    
    464 F. Supp. 3d 455
    , 461 (D. Mass. 2020).
    On this interlocutory appeal, we now affirm the district
    court's denial of D&Z's motion.1
    I.
    The following facts are not in dispute.               Waters formerly
    worked      for    D&Z   in    Plymouth,     Massachusetts.       He    served     as   a
    mechanical supervisor for the company, which provides services to
    power plants.
    On July 22, 2019, Waters filed an FLSA-based "collective
    action" complaint against D&Z.                That complaint alleged that D&Z
    violated the FLSA's overtime-wage provisions, see § 207(a)(1),
    because it "paid Waters and other workers like him the same hourly
    We acknowledge with appreciation the assistance of the
    1
    amicus curiae in this case.
    - 4 -
    rate for all hours worked, including those in excess of 40 in a
    workweek."     Waters sought unpaid overtime wages as liquidated
    damages, and attorneys' fees on behalf of himself and "the Putative
    Class Members."
    About two weeks later, on August 8, 2019, Waters served
    the complaint on D&Z pursuant to 4(c) of the FRCP, utilizing the
    provisions of Massachusetts' long-arm statute.       Mass. Gen. Laws
    ch. 223A, § 3.    The following month, others claiming to be current
    or former D&Z employees filed written "opt-in" consent forms
    pursuant to § 216(b) in the district court to participate in the
    collective action that Waters had filed.
    The standard opt-in consent form contained the following
    language:
    1. I hereby consent to participate in a
    collective action lawsuit against Day &
    Zimmermann to pursue my claims of unpaid
    overtime during the time that I worked with
    the company.
    2. I understand that this lawsuit is brought
    under the Fair Labor Standards Act, and
    consent to be bound by the Court's decision.
    3. I designate the law firm and attorneys at
    JOSEPHSON DUNLAP and BRUCKNER BURCH as my
    attorneys to prosecute my wage claims.
    4. I authorize the law firm and attorneys at
    JOSEPHSON DUNLAP and BRUCKNER BURCH to use
    this consent to file my claim in a separate
    lawsuit,   class/collective    action,   or
    arbitration against the company.
    - 5 -
    To date, over 100 opt-ins claiming to be current and former D&Z
    employees have filed consent forms electing to participate in the
    FLSA collective action that Waters filed.
    On   September   12,   2019,     D&Z   moved     pursuant    to   FRCP
    12(b)(2) to dismiss the claims of those opt-ins who had not been
    employed by D&Z in Massachusetts.              D&Z explained that, in so
    moving, it did not seek to "challenge personal jurisdiction as to
    the named Plaintiff's [i.e., Waters's] individual claim, as he
    allege[d] that he previously worked for [D&Z] in Massachusetts."
    Nor did D&Z contend that it had not properly been served with
    process or that anyone other than the named plaintiff was required
    to serve D&Z with process.     Instead, D&Z's motion and accompanying
    memorandum of law claimed that BMS required the dismissal of the
    opt-in claims because the district court lacked either general or
    specific personal jurisdiction as to those claims.
    In BMS, the Supreme Court held that the Fourteenth
    Amendment's Due Process Clause prevented a California state court
    from exercising specific personal jurisdiction over nonresident
    plaintiffs' state-law claims when those claims had no connection
    to the forum state.      137 S. Ct. at 1781.          The decision expressly
    reserved   the   separate    question      "whether    the    Fifth     Amendment
    imposes    the   same   restrictions    on    the     exercise    of    personal
    jurisdiction by a federal court."          Id. at 1784.
    - 6 -
    On June 2, 2020, the district court here denied D&Z's
    motion to dismiss the opt-in claims based on BMS.              It determined
    that the Supreme Court's ruling in that case had no bearing on its
    exercise   of   personal    jurisdiction   over    the   opt-ins     because
    Waters's suit was brought in federal court pursuant to the FLSA's
    provisions   governing     collective   actions,   and   the    opt-ins   had
    joined his suit in accord with that statute's procedures for doing
    so.   Waters, 464 F. Supp. 3d at 461.       In reaching this decision,
    the district court noted that BMS was "specifically limited to
    'the due process limits on the exercise of specific jurisdiction
    by a State'" and did not resolve "whether the Fifth Amendment
    imposes the same restrictions" on a federal court.              Id. (quoting
    BMS, 137 S. Ct. at 1783–84).
    Following the denial, D&Z moved in the district court
    for a certificate of appealability under 
    28 U.S.C. § 1292
    (b),
    which the district court granted, see Waters v. Day & Zimmermann
    NPS, Inc., No. 19-cv-11585-NMG, 
    2020 WL 4754984
    , at *1 (D. Mass.
    Aug. 14, 2020).     This court granted D&Z's timely petition for
    permission to bring an interlocutory appeal on October 14, 2020.2
    We have appellate jurisdiction under 
    28 U.S.C. § 1292
    (b).
    2The district court has stayed the proceedings below pending
    our resolution of D&Z's interlocutory appeal.
    - 7 -
    II.
    Before addressing the merits of D&Z's appeal, we first
    consider an issue that neither party raises, but that could affect
    our appellate jurisdiction: whether the opt-in plaintiffs were
    parties to the action in the district court.           If the dismissed
    opt-in plaintiffs were not parties to the action, we may lack
    jurisdiction to consider the propriety of their dismissal.             See
    Campbell v. City of Los Angeles, 
    903 F.3d 1090
    , 1105 (9th Cir.
    2018) ("All 'those that properly become parties[] may appeal an
    adverse judgment.'" (quoting Marino v. Ortiz, 
    484 U.S. 301
    , 304
    (1988))). The opt-ins' party status hinges on the question whether
    they become parties as a result of filing opt-in notices, or they
    could become parties only after the district court conditionally
    certified that they were "similarly situated."
    The   FLSA   provides   that    employees   serving   as   named
    plaintiffs can bring collective actions on "behalf of . . .
    themselves and other employees similarly situated."             § 216(b).
    The FLSA does not provide for conditional certification, but in
    the "absence of statutory or case law guidance," district courts
    at or around the pleading stage have developed a "loose consensus"
    regarding conditional certification procedures.           Campbell, 903
    F.3d at 1108–09.   This process entails a "lenient" review of the
    pleadings, declarations, or other limited evidence, id. at 1109
    (citation omitted), to assess whether the "proposed members of a
    - 8 -
    collective are similar enough to receive notice of the pending
    action," Swales v. KLLM Transp. Servs., L.L.C., 
    985 F.3d 430
    , 436
    (5th Cir. 2021).
    Conditional certification has no bearing on whether the
    opt-in plaintiffs become parties to the action.   The FLSA provides
    that "[n]o employee shall be a party plaintiff to any such action
    unless he gives his consent in writing to become such a party and
    such consent is filed in the court in which such action is
    brought." § 216(b). This provision makes clear that in collective
    actions, opt-in plaintiffs become parties to the proceedings when
    they give "consent in writing to become such a party and such
    consent is filed in the court."3   Id.
    Conditional certification cannot be the cornerstone of
    party status because it is not a statutory requirement; rather,
    certification "is a product of interstitial judicial lawmaking or
    3The relevant portion of subsection (b) reads as
    follows, in part:
    An action to recover the liability prescribed
    in the preceding sentences may be maintained
    against any employer (including a public
    agency) in any Federal or State court of
    competent jurisdiction by any one or more
    employees for and in behalf of himself or
    themselves and other employees similarly
    situated. No employee shall be a party
    plaintiff to any such action unless he gives
    his consent in writing to become such a party
    and such consent is filed in the court in which
    such action is brought.
    - 9 -
    ad hoc district court discretion . . . nothing in section 216(b)
    expressly compels it."        Campbell, 903 F.3d at 1100; see also Myers
    v. Hertz Corp., 
    624 F.3d 537
    , 555 n.10 (2d Cir. 2010) ("Thus
    'certification'       is   neither     necessary      nor   sufficient     for    the
    existence of a representative action under [the] FLSA, but may be
    a useful 'case management' tool for district courts to employ in
    'appropriate cases.'" (quoting Hoffmann-La Roche Inc. v. Sperling,
    
    493 U.S. 165
    , 169, 174 (1989))).
    Both the Supreme Court and nearly all of our sister
    circuits that have considered the question agree that opt-in
    plaintiffs     become      parties    to   the   action      without    regard     to
    conditional certification.            Genesis Healthcare Corp. v. Symczyk,
    
    569 U.S. 66
    , 75 (2013), concerned the justiciability of an FLSA
    collective action when the named plaintiff's claims became moot
    and no opt-in plaintiffs had joined in the action prior to that
    occurring.     See Symczyk v. Genesis Healthcare Corp., 
    656 F.3d 189
    ,
    197 (3d Cir. 2011) (noting that "no other potential plaintiff ha[d]
    opted in to the suit").         The Supreme Court rejected the idea that
    the   action    was    not   moot     because    it    could    be     remanded    to
    conditionally     certify       the     collective,         since    "'conditional
    certification' does not produce a class with an independent legal
    status, or join additional parties to the action.                         The sole
    consequence of conditional certification is the sending of court-
    approved written notice to employees . . . who in turn become
    - 10 -
    parties to a collective action only by filing written consent with
    the court."   Genesis Healthcare, 
    569 U.S. at 75
     (first citing
    Hoffmann-La Roche, 493 U.S. at 171-72; then citing § 216(b)).
    Almost all circuits to address this issue interpret the
    statute as making opt-in plaintiffs parties to the action as soon
    as they file consent forms.   See, e.g., Campbell, 903 F.3d at 1104
    ("The FLSA leaves no doubt that 'every plaintiff who opts in to a
    collective action has party status.'" (quoting Halle v. W. Penn
    Allegheny Health Sys. Inc., 
    842 F.3d 215
    , 225 (3d Cir. 2016)));
    Mickles v. Country Club Inc., 
    887 F.3d 1270
    , 1278 (11th Cir. 2018)
    ("The plain language of § 216(b) supports that those who opt in
    become party plaintiffs upon the filing of a consent and that
    nothing   further,   including   conditional   certification,   is
    required."); Simmons v. United Mortg. and Loan Inv., LLC, 
    634 F.3d 754
    , 758 (4th Cir. 2011) ("[I]n a collective action under the FLSA,
    a named plaintiff represents only himself until a similarly-
    situated employee opts in as a 'party plaintiff' by giving 'his
    consent in writing to become such a party and such consent is filed
    in the court in which such action is brought.'" (quoting § 216(b));
    Anson v. Univ. of Tex. Health Sci. Ctr. at Hous., 
    962 F.2d 539
    ,
    540 (5th Cir. 1992) ("Under Section 216(b), an employee may become
    an 'opt-in' party plaintiff to an already filed suit by filing
    written consent with the court where the suit is pending.").    D&Z
    also agrees that once an opt-in plaintiff "file[s] their consent
    - 11 -
    with the court, [they] have full party status."        Appellant's Br.
    26 (emphasis in original); see also id. at 2.
    The sole possible exception to the general recognition
    that opt-in plaintiffs become parties to the action upon filing
    consent forms is the Seventh Circuit's decision in Hollins v.
    Regency Corp., 
    867 F.3d 830
    , 833 (7th Cir. 2017), which held that
    appellate review of a named plaintiff's adverse summary judgment
    decision was not precluded by the presence of other parties when
    "the collective action has never been conditionally certified and
    the court has not in any other way accepted efforts by the unnamed
    members   to   opt   in   or   intervene."   The   decision   attributed
    significance to the district court's failure to conditionally
    certify the collective action, or to "accept[] efforts by the
    unnamed members to opt in or intervene."      
    Id.
     at 833–34.    There is
    no indication that the Hollins court would find lack of party
    status in a case like this, in which the opt-in forms were accepted
    as filed by the district court.
    Although Canaday v. Anthem Cos., 
    9 F.4th 392
     (6th Cir.
    2021), and Vallone v. CJS Solutions Group, 
    9 F.4th 861
     (8th Cir.
    2021), reached a different ultimate result on the question of
    personal jurisdiction, both support our view that the dismissed
    opt-in plaintiffs were parties to the action.           In Canaday and
    Vallone, the Sixth and Eighth Circuits faced the same BMS-based
    personal jurisdiction challenge that D&Z raises now.           In those
    - 12 -
    cases, opt-in plaintiffs had joined the action by filing consent
    forms.    Both district courts resolved the defendants' personal
    jurisdiction challenges and dismissed the out-of-state opt-in
    claims before reaching the merits of the in-state plaintiffs'
    requests for conditional certification, signifying that it was not
    necessary to decide the certification issue first.         See Canaday v.
    Anthem Cos., 
    439 F. Supp. 3d 1042
    , 1049 (W.D. Tenn. 2020); Vallone
    v. CJS Sols. Grp., 
    437 F. Supp. 3d 687
    , 691 (D. Minn. 2020).          The
    Sixth    Circuit   explicitly   agreed   that   the   nonresident   opt-in
    plaintiffs became parties regardless of conditional certification,
    stating that "[o]nce they file a written consent, opt-in plaintiffs
    enjoy party status as if they had initiated the action," Canaday,
    9 F.4th at 394, and "once they opt in, these plaintiffs become
    'party plaintiff[s]' . . . enjoying 'the same status in relation
    to the claims of the lawsuit as do the named plaintiffs,'" id. at
    402–03 (first quoting § 216(b); then quoting Prickett v. DeKalb
    County, 
    349 F.3d 1294
    , 1297 (11th Cir. 2003)).4
    We note that collective actions are distinct from FRCP
    23 class actions in that the latter's putative class members do
    not become parties until after certification, see Smith v. Bayer
    Corp., 
    564 U.S. 299
    , 315 (2011), and putative class members who
    have not intervened in an action cannot appeal denials of class
    4 The Eighth Circuit did not appear to address this question
    but did not disagree with the district court's approach.
    - 13 -
    certification, Deposit Guaranty Nat'l Bank v. Roper, 
    445 U.S. 326
    ,
    330, 332 n.5 (1980) (citing United Airlines, Inc. v. McDonald, 
    432 U.S. 385
     (1977)); see also Molock v. Whole Foods Mkt. Grp., Inc.,
    
    952 F.3d 293
    , 298 (D.C. Cir. 2020) ("Putative class members become
    parties to an action—and thus subject to dismissal—only after class
    certification."). These Rule 23 class action cases have no bearing
    on whether the opt-in plaintiffs here became parties to the action.
    In short, the FLSA's text, Supreme Court precedent, and
    a majority of circuit court decisions compel only one conclusion:
    the opt-ins who filed consent forms with the court became parties
    to the suit upon filing those forms.      Nothing else is required to
    make them parties.   Because more than 100 current and former D&Z
    employees filed consent waivers in the district court, there are
    that many opt-in party-plaintiffs before this court.          We proceed
    to decide whether the district court properly denied D&Z's motion
    to dismiss the nonresident opt-in claims for lack of personal
    jurisdiction.
    III.
    D&Z   argues   that   BMS   requires   our   dismissal   of   the
    nonresident opt-in claims because the Massachusetts district court
    lacked either general or specific personal jurisdiction as to those
    claims.   A detailed description of BMS provides helpful context.
    In BMS, a group of nearly 700 plaintiffs filed eight separate
    complaints in California state court alleging state-law products
    - 14 -
    liability, negligent misrepresentation, and misleading advertising
    claims.   137 S. Ct. at 1778.         The plaintiffs' purported injuries
    all stemmed from Plavix, a drug manufactured and sold by BMS.                Id.
    Pursuant to a California procedural rule that permitted post-hoc
    consolidation of the eight separate complaints, the plaintiffs
    combined their suits into one mass-tort action.5                  See Bristol-
    Myers Squibb Co. v. Superior Court of California, 
    175 Cal. Rptr. 3d 412
    , 416 (Ct. App. 2014).             The combined suit consisted of a
    majority of non-resident plaintiffs, none of whom obtained Plavix
    in California, used the drug there, or received treatment for their
    injuries there.      
    Id.
         BMS did, however, sell 187 million Plavix
    pills in California, and it earned more than $900 million from
    those sales.   
    Id.
    Citing these "extensive contacts with California" and
    the   similarity   of      the   resident   and    nonresident    claims,   the
    California   Supreme    Court     held    that    the   state   could   properly
    exercise specific jurisdiction over the mass-action.              
    Id. at 1779
    .
    Rejecting this conclusion, the U.S. Supreme Court held that the
    Fourteenth Amendment's Due Process Clause prohibits state courts
    from exercising specific personal jurisdiction over state-law
    claims asserted by nonresident plaintiffs absent a "connection
    5In California, "coordination" allows complex civil actions
    that are "pending in different courts," but that share "a common
    question of fact or law" to be consolidated in one proceeding.
    Cal. Civ. Proc. § 404.
    - 15 -
    between the [state] forum and the specific claims at issue."                    Id.
    at 1781, 1783.       Similarities between the nonresident claims and
    the claims of residents or those who were injured in California
    were insufficient to establish that connection.                  Id. at 1781.
    The    decision     emphasized        that   the    "burden   on     [a]
    defendant"—the       "primary       concern"       animating       jurisdictional
    restrictions—encompasses more than just the "practical problems
    resulting from litigating in the forum."                   Id. at 1780.        These
    restrictions      also   protect    defendants      from    "submitting    to    the
    coercive power of a State that may have little legitimate interest
    in the claims in question," a "federalism interest" that is "at
    times . . . decisive."        Id.    The Supreme Court explained:
    [E]ven if the defendant would suffer minimal
    or no inconvenience from being forced to
    litigate before the tribunals of another
    State; even if the forum State has a strong
    interest   in   applying   its   law   to   the
    controversy; even if the forum State is the
    most convenient location for litigation, the
    Due Process Clause, acting as an instrument of
    interstate federalism, may sometimes act to
    divest the State of its power to render a valid
    judgment.
    Id. at 1780-81 (quoting World-Wide Volkswagen Corp. v. Woodson,
    
    444 U.S. 286
    , 294 (1980)).
    The    Court's    reasoning      in    BMS     rests   on   Fourteenth
    Amendment    constitutional         limits   on     state      courts   exercising
    jurisdiction over state-law claims.               Here, it is agreed that the
    Fourteenth Amendment does not directly limit a federal court's
    - 16 -
    jurisdiction   over   purely   federal-law   claims.   Rather,    as   a
    constitutional matter, the "constitutional limits" of a federal
    court's jurisdiction over federal-law claims "are drawn in the
    first instance with reference to the [D]ue [P]rocess [C]lause of
    the [F]ifth [A]mendment," a point which D&Z concedes, as it must.
    See Lorelei Corp. v. County of Guadalupe, 
    940 F.2d 717
    , 719 (1st
    Cir. 1991).    The Fifth Amendment does not bar an out-of-state
    plaintiff from suing to enforce their rights under a federal
    statute in federal court if the defendant maintained the "requisite
    'minimum contacts' with the United States."6       See United Elec.,
    Radio & Mach. Workers of Am. v. 163 Pleasant St. Corp., 
    960 F.2d 1080
    , 1085 (1st Cir. 1992).     There is no contention here that the
    opt-in plaintiffs lack such contacts with the United States; that
    the Fifth or Fourteenth Amendments themselves bar suit by the non-
    resident opt-in plaintiffs; or that BMS directly governs a suit in
    federal court under a federal statute, such as this one.         Nor is
    there any contention that D&Z was not properly served with process
    pursuant to FRCP 4(c) and the Massachusetts long-arm statute.
    Nonetheless, D&Z claims that the Fifth Amendment is
    "wholly irrelevant" to the personal jurisdiction question before
    6 "Because the United States is a distinct sovereign, a
    defendant may in principle be subject to the jurisdiction of the
    courts of the United States but not of any particular State." J.
    McIntyre Mach., Ltd. v. Nicastro, 
    564 U.S. 873
    , 884 (2011)
    (plurality opinion).
    - 17 -
    us—notwithstanding that this is a federal question case being heard
    in federal court—because Rule 4(k) "incorporates the Fourteenth
    Amendment's limits on the jurisdiction of federal courts wherever
    a federal statute does not provide for nationwide service of
    process."     In other words, they propose that Rule 4 is not
    concerned   merely   with     service    of       process,   but    with   personal
    jurisdiction generally.        Thus, D&Z argues, because there is no
    dispute that the FLSA does not authorize nationwide service of
    process,    Rule   4(k)   independently           makes    the   holding    of    BMS
    applicable to the FLSA opt-ins.
    This   argument    depends       on    the    contention      that   Rule
    4(k)(1) governs not just service of a summons, but also limits a
    federal court's jurisdiction after the summons is properly served.
    We must decide whether D&Z is right that Rule 4(k)(1) operates as
    a   free-standing     limitation        on    the        exercise    of    personal
    jurisdiction in collective actions such as those enabled by the
    FLSA.   We do not find D&Z's contention persuasive, as we now
    discuss.
    IV.
    The question before us is one of rule interpretation.
    As such, our review is de novo.              See Sam M. ex rel. Elliott v.
    Carcieri, 
    608 F.3d 77
    , 86 (1st Cir. 2010) (citing NEPSK, Inc. v.
    Town of Houlton, 
    283 F.3d 1
    , 5 (1st Cir. 2002)).
    - 18 -
    A.
    We start with the relevant text.         The text reveals that
    Rule 4   is limited to setting         forth various requirements        for
    effectively serving a summons on a defendant in federal court,
    thereby establishing personal jurisdiction over the defendant.
    BNSF Ry. Co. v. Tyrrell, 
    137 S. Ct. 1549
    , 1556 (2017) ("[A] basis
    for service of a summons on the defendant is prerequisite to the
    exercise of personal jurisdiction." (citing Omni Cap. Int'l, Ltd.
    v. Rudolf Wolff & Co., 
    484 U.S. 97
    , 104 (1987)); see also Walden
    v. Fiore, 
    571 U.S. 277
    , 283 (2014) ("[A] federal district court's
    authority to assert personal jurisdiction in most cases is linked
    to service of process on a defendant."); Canaday, 9 F.4th at 395
    ("Over time, service of process became a prerequisite for obtaining
    authority over a defendant, making it appropriate to say that
    'service of process conferred jurisdiction.'" (quoting Burnham v.
    Superior Ct. of Cal., 
    495 U.S. 604
    , 613 (1990))).
    Indeed, Rule 4's title, "Summons," suggests that it is
    concerned    only   with   service.        The    notes   accompanying   the
    committee's 1993 amendment to Rule 4 reveal that the title was
    changed from "Process"      to "Summons"         to show that   the rule's
    requirements "applie[d] only to that form of legal process."
    Amendments to Fed. R. Civ. P. 4, 
    146 F.R.D. 401
    , 559 (1993).
    Turning to subsection (k) of Rule 4, it is apparent that
    it addresses an aspect of how a summons may be served.             Like the
    - 19 -
    rule as a whole, it, too, bears a title that adverts to the
    requirements for effecting service of a summons: "Territorial
    Limits of Effective Service."       Specifically, paragraph (1) of
    subsection (k) limits the instances in which "[s]erving a summons
    or filing a waiver of service establishes personal jurisdiction
    over a defendant":
    (k) Territorial Limits of Effective Service.
    (1) In General. Serving a summons or
    filing a waiver of service establishes
    personal jurisdiction over a defendant:
    (A)   who   is   subject   to   the
    jurisdiction of a court of general
    jurisdiction in the state where the
    district court is located;
    (B) who is a party joined under Rule
    14 or 19 and is served within a
    judicial district of the United
    States and not more than 100 miles
    from where the summons was issued;
    or
    (C) when    authorized   by   federal
    statute.
    Fed. R. Civ. P. 4(k)(1)(A)–(C) (emphasis added).     Thus, while the
    text states that personal jurisdiction can be "establishe[d]" by
    "[s]erving a summons" so long as any of these three criteria is
    met, it nowhere suggests that Rule 4 deals with anything other
    than service of a summons, or that Rule 4 constrains a federal
    court's power to act once a summons has been properly served, and
    personal jurisdiction has been established.
    We see no textual basis in Rule 4 for concluding that
    the district court's exercise of jurisdiction over the opt-in
    - 20 -
    claims would be improper when "there is no dispute the named
    plaintiff properly served [D&Z]" by serving a summons in accord
    with Rule 4(c); D&Z does not contend that such service failed to
    satisfy the territorial limits of Rule 4(k)(1)(A) given that Waters
    had been employed by D&Z in Massachusetts; see United Electric,
    
    960 F.2d at
    1087 (citing Mass. Gen. Laws ch. 223A, § 3), and D&Z
    conceded that the opt-ins are not "responsible" for serving a
    summons.7
    To be sure, Rule 4(k)(1)(A) does make the due process
    standard    of   the   Fourteenth   Amendment   applicable   to   federal-
    question claims in federal court when a plaintiff relies on a state
    long-arm statute for service of the summons.            Rule 4(k)(1)(A)
    requires looking to state law to determine whether service is
    effective to confer jurisdiction, and "because state law is subject
    to   Fourteenth    Amendment    limitations,     the   minimum    contacts
    doctrine, while imposing no direct state-by-state constraint on a
    federal court in a federal question case, acts indirectly as a
    governing mechanism for the exercise of personal jurisdiction."
    United Electric, 
    960 F.2d at 1086
    .       But this is not the same thing
    as saying that Rule 4 or the Fourteenth Amendment governs district
    7 The Sixth Circuit in Canaday agreed that the opt-ins have
    no service obligations under Rule 4. 9 F.4th at 399–400 ("After
    Anthem appeared in the case in response to Canaday's service of
    the complaint, it is true, the nonresident plaintiffs . . . had no
    additional service obligation under Civil Rule 4(k).").
    - 21 -
    court jurisdiction in federal question cases after a summons has
    been properly served; had it been the FRCP drafters' intention to
    have Rule 4 govern more than the service of a summons, they could
    have simply said that additional plaintiffs may be added to an
    action    if   they   could   have   served     a   summons   on   a   defendant
    consistent with Rule 4(k)(1)(A).         But that was not the choice the
    drafters made, and for good reason.           It would be anomalous to apply
    the Fourteenth Amendment, rather than the Fifth Amendment, to
    federal causes of action after a summons is properly served.8
    Significantly, FRCP 82 also states that "[t]hese rules do not
    extend or limit the jurisdiction of the district courts."                Fed. R.
    Civ. P. 82; see also Miss. Publ'g Corp. v. Murphree, 
    326 U.S. 438
    ,
    445   (1946)   ("Rule   [4(k)(1)(A)]     serves      only   to   implement   the
    jurisdiction . . . Congress has conferred, by providing a procedure
    by which the defendant may be brought into court at the place where
    Congress has declared that the suit may be maintained.")
    8The dissent cites various law review articles suggesting
    changes to Rule 4(k) that would expand the jurisdiction of federal
    courts. See Scott Dodson, Personal Jurisdiction and Aggregation,
    113 NW. U. L. REV. 1, 37-40 (2018); see also Stephen E. Sachs, How
    Congress Should Fix Personal Jurisdiction, 108 NW. U. L. REV. 1301,
    1316 (2014); A. Benjamin Spencer, The Territorial Reach of Federal
    Courts, 71 FLA. L. REV. 979, 990-91 (2019). With one exception,
    see infra note 12, none of the articles discusses the particular
    issue addressed here: whether Rule 4(k) continues to apply after
    service of process has been effectuated.
    - 22 -
    B.
    Apart from the text of Rule 4(k), its history shows that
    its limited purpose was to govern service of a summons, not to
    limit the jurisdiction of the federal courts after a summons has
    been served.     The first version of Rule 4(f), (now Rule 4(k))
    entitled "Territorial Limits of Effective Service," required that
    for process to be effectively served, it must be physically served
    "anywhere within the territorial limits of the state in which the
    district court is held" unless a federal statute authorized service
    "beyond the territorial limits of that state."             Fed. R. Civ. P.
    4(f) (1937).     This geographical limit prevented a plaintiff from
    serving a defendant anywhere outside of the state in which the
    underlying lawsuit would take place, consistent with the then-
    geographically-based concept of "tag" jurisdiction.              See Pennoyer
    v. Neff, 
    95 U.S. 714
    , 733 (1878).
    Due to the "changes in the technology of transportation
    and   communication,    and   the    tremendous   growth    of    interstate
    business activity," business operations transcended the bounds of
    any one state, rendering jurisdiction based on physical presence
    largely obsolete.      Daimler AG v. Bauman, 
    571 U.S. 117
    , 126 (2014)
    (quoting Burnham, 
    495 U.S. at 617
    ).          Responding to this change,
    International Shoe Co. v. Washington, 
    326 U.S. 310
    , 316 (1945)
    (quoting Milliken v. Meyer, 
    221 U.S. 457
    , 463 (1940)), eliminated
    the   physical   presence     requirement,    holding   that       Fourteenth
    - 23 -
    Amendment due process is satisfied for jurisdictional purposes
    when a defendant has "certain minimum contacts [with the forum]
    such that the maintenance of the suit does not offend 'traditional
    notions of fair play and substantial justice.'"
    The     1963    version       of     Rule    4(f),    also        entitled
    "Territorial       Limits     of     Effective      Service,"      reflected       the
    principles set forth in International Shoe. Citing "[a]n important
    and growing class of State [long-arm] statutes [that] base personal
    jurisdiction over nonresidents on the doing of acts or on other
    contacts within the State," Rule 4 was amended to "expressly
    allow[] resort in original Federal actions to the procedures
    provided     by    State    law    for   effecting       service   on    nonresident
    parties."     Amendments to Fed. R. Civ. P. 4, 
    31 F.R.D. 587
    , 627-28
    (1963).      Specifically, Rule           4(f) was       "amended to assure        the
    effectiveness of service outside the territorial limits of the
    State" when allowed by state law.                 
    Id. at 629
     (emphasis added).
    The amended text allowed process to be served "anywhere within the
    territorial limits of the state in which the district court is
    held, and, when authorized by a statute of the United States or by
    these rules, beyond the territorial limits of that state."                       
    Id. at 594
    .
    Later amendments to other provisions of Rule 4 also show
    that   the    rule    evolved      to    simplify    service,      not    to    govern
    jurisdiction after service.               The 1980 amendments expanded the
    - 24 -
    category of individuals who could act as process servers from
    marshals, deputies, and individuals specifically appointed by the
    court to include any person "authorized to serve process in an
    action brought in the courts of general jurisdiction of the state
    in which the district court is held or in which service is made."
    Amendments to Fed. R. Civ. P. 4, 
    85 F.R.D. 521
    , 524 (1980). Despite
    this expansion, the 1983 amendments recognized that the job of
    serving process still largely fell on marshals in states that did
    not authorize additional process servers, and they also reflected
    views that mail service and other methods of service prescribed by
    state law were of paramount importance.              Amendments to Fed. R.
    Civ. P. 4, 
    96 F.R.D. 81
    , 118-19 (1983).                The 1983 amendments
    overhauled Rule 4(c) (now Rule 4(c), (e)) to allow a summons to
    "be served by any person who is not a party and is not less than
    18 years of age" and permitted service "by mailing a copy of the
    summons . . . to the person to be served."               
    Id.
     at 82–83.       In
    response    to   efforts    to   "delete[]    the   provision"   authorizing
    service pursuant to the law of the forum state, the 1983 amendments
    "saw   no   reason   to    forego   systems   of    service   that   had   been
    successful in achieving effective notice," and incorporated that
    provision into the new version of Rule 4(c).            
    Id. at 83, 119
    .
    The final amendment to Rule 4(k) occurred in 1993.
    Subdivision (f) became subdivision (k), and the committee notes
    emphasized that the amendment's purpose was to "facilitate the
    - 25 -
    service     of       the    summons       and   complaint"    and     to    "explicitly
    authorize[] a means for service of the summons and complaint on
    any defendant."            146 F.R.D. at 558.        The amended rule "retain[ed]
    the substance of the former rule" by "explicitly authorizing the
    exercise of personal jurisdiction over persons who can be reached
    under state long-arm law."                Id. at 570.
    The fact that 4(k)(1)(A) provides that "service of a
    summons"    establishes personal jurisdiction                  over defendants        by
    utilizing        a    given     state's         long-arm    statute        incorporating
    Fourteenth       Amendment         requirements      does    not    show      that   the
    Fourteenth Amendment applies to federal-law claims after service
    is satisfied.         See 4 Charles A. Wright, Arthur R. Miller & Adam N.
    Steinman, Federal Practice and Procedure § 1007 (4th ed. 2021)
    ("The rule was also amended to clarify when service of a summons
    would establish personal jurisdiction in federal court.").                            In
    fact, the advisory committee notes make clear that a federal
    court's     jurisdiction           once    service    has    been     effectuated     is
    determined by the Fifth Amendment's Due Process Clause at least in
    federal actions.            146 F.R.D. at 566 ("Service of the summons under
    this subdivision does not conclusively establish the jurisdiction
    of the court over the person of the defendant.                        A defendant may
    assert the territorial limits of the court's reach set forth in
    subdivision (k), [i.e. whether the service is effective under state
    or   federal          law     to      confer      jurisdiction]       including      the
    - 26 -
    constitutional limitations that may be imposed by the Due Process
    Clause of the Fifth Amendment."). Thus, although serving a summons
    in accordance with state or federal law is necessary to establish
    jurisdiction over a defendant in the first instance, the Fifth
    Amendment's constitutional limitations limit the authority of the
    court after service has been effectuated at least in federal-law
    actions.
    C.
    Another reason that we cannot read Rule 4(k)(1)(A) as
    limiting the court's authority over the added plaintiffs is that
    FRCP 20 already defines that authority.     Rule 20 sets the limit
    for allowing additional parties to join a pre-existing lawsuit,
    permitting joinder of those parties with claims arising out of the
    "same   transaction   [or]   occurrence"   and   presenting   common
    "question[s] of law or fact."     Fed. R. Civ. P. 20(a)(1)(A), (B).
    The FLSA's "similarly situated" limitation for collective actions
    displaces Rule 20 and limits the range of individuals who may be
    added as opt-in plaintiffs by requiring that they be "similarly
    situated."   See, e.g., Cruz v. Bristol-Myers Squibb Co., PR, 
    699 F.3d 563
    , 569 (1st Cir. 2012) (The similarly situated "requirement
    is even less stringent than the test for party joinder" (citations
    omitted)); Campbell, 903 F.3d at 1104–05 ("The natural parallel is
    to plaintiffs . . . later added under the ordinary rules of party
    joinder."); Chamber of Comm. Br. 12 ("[T]he FLSA's opt-in provision
    - 27 -
    is properly viewed as a rule of joinder." (citation omitted)).                We
    are not aware of, and D&Z has not cited, a case in which a court
    held that Rule 4 applies to plaintiffs joined under Rule 20.
    Finally, the FLSA and its legislative history show that
    Congress created the collective action mechanism to enable all
    affected employees working for a single employer to bring suit in
    a single, collective action.            The FLSA's purpose was to allow
    efficient enforcement of wage and hour laws against large, multi-
    state employers, a "broad remedial goal" that the Supreme Court
    has instructed "should be enforced to the full extent of its
    terms."     Hoffman-La Roche, 493 U.S. at 173.
    The     FLSA's   original     premise   was     to   target    those
    employers    engaged    in   interstate    commerce,      defined   as    "trade,
    commerce, transportation, transmission, or communication among the
    several States or from any State to any place outside thereof."
    Fair Labor Standards Act of 1938, ch. 676, § 3(b), 
    52 Stat. 1060
    .
    Specifically, the legislative history evinces congressional intent
    to "provide a living wage" for workers at large, multi-state
    businesses, such as Sears Roebuck, General Motors, and Coca-Cola.
    82 Cong. Rec. 1815–16 (1937) (remarks of Rep. Adolph Sabath); see
    also   93   Cong.    Rec.    2182   (1947)   (remarks      of    Sen.    Donnell)
    (contemplating a suit in which "John Smith files a suit on behalf
    of himself and all other employees of the United States Steel
    Corporation" (emphasis added)).           The congressional debates also
    - 28 -
    reveal a clear intent for a collective action to allow a "suit by
    one   or   more   employees,   for    himself    and   all   other   employees
    similarly situated," regardless of the state in which they were
    employed.     
    Id.
     (emphasis added).
    Interpreting the FLSA to bar collective actions by out-
    of-state employees would frustrate a collective action's two key
    purposes: "(1) enforcement (by preventing violations and letting
    employees pool resources when seeking relief); and (2) efficiency
    (by resolving common issues in a single action)."                Swales, 985
    F.3d at 435 (citing Bigger v. Facebook, 
    947 F.3d 1043
    , 1049 (7th
    Cir. 2020)); see also Hoffman-La Roche, 493 U.S. at 170 ("A
    collective action allows . . . plaintiffs the advantage of lower
    individual costs to vindicate rights by the pooling of resources.
    The   judicial    system   benefits    by     efficient   resolution   in   one
    proceeding of common issues of law and fact arising from the same
    alleged discriminatory activity.").
    Holding that a district court lacks jurisdiction over
    the non-resident opt-in claims would "force[] those plaintiffs to
    file separate lawsuits in separate jurisdictions against the same
    employer based on the same or similar alleged violations of the
    FLSA."     Canaday, 9 F.4th at 415–16 (Donald, J., dissenting).             That
    is not what the FLSA contemplated.
    - 29 -
    V.
    As we have noted earlier, the Sixth and Eighth Circuits,
    faced with BMS-based personal jurisdiction challenges to FLSA
    collective actions, disagree with the decision that we reach today.
    Neither decision suggests that the Fourteenth Amendment directly
    limits federal-court authority to entertain multi-state collective
    actions.       Both opinions instead rely on an erroneous reading of
    Rule 4, and fail to successfully confront the fact that Rule 4(k)
    is a "territorial limit" on "effective service" of a summons, and
    thus       logically   cannot   be   read   to   limit   a   federal    court's
    jurisdiction after a summons is properly served.
    In   this   respect,   the    Eighth   Circuit,    with    little
    discussion, reached the same result as the Sixth Circuit, ruling
    it "a given" that the Fourteenth Amendment, by way of Rule 4,
    limited the court's jurisdiction with respect to all of the claims,
    including those of the opt-in plaintiffs.                Vallone, 9 F.4th at
    865.       The Sixth Circuit opinion is more expansive.9        It concluded
    that even for "amended complaints and opt-in notices, the district
    court remains constrained by . . . the host State's [] personal
    jurisdiction limitations." Canaday, 9 F.4th at 400 (citing Tamburo
    v. Dworkin, 
    601 F.3d 693
    , 700–01 (7th Cir. 2010)).              But Tamburo,
    the only case cited in support of this proposition, is silent on
    The Sixth Circuit's decision was an interlocutory appeal
    9
    pursuant to 
    28 U.S.C. § 1292
    (b). See Canaday, 9 F.4th at 395.
    - 30 -
    whether Rule 4 concerns the scope of personal jurisdiction after
    service of a summons.    The case involved only a single, original
    plaintiff and the original defendants.        The sole plaintiff served
    a summons under Rule 4 and the state's long-arm statute.        See 
    601 F.3d at 698, 700
    . Since the personal jurisdiction issue in Tamburo
    concerned only the original plaintiff's state-law claims, 
    id.
     at
    700–01, the court had no occasion to consider its jurisdiction
    over federal claims or parties added after a summons was properly
    served.10
    The other authorities relied on by the Sixth Circuit do
    not come close to addressing whether 4(k) and the Fourteenth
    Amendment apply to federal-law claims after a summons has been
    properly served pursuant to a state long-arm statute.11 See Handley
    v. Ind. & Mich. Elec. Co., 
    732 F.2d 1265
    , 1269 (6th Cir. 1984)
    (affirming    district   court's   exercise     of   jurisdiction   over
    nonresident defendant served by original plaintiff pursuant to
    10The Seventh Circuit affirmed the district court's 12(b)(6)
    dismissal of the federal-law claims before addressing personal
    jurisdiction over the state-law claims. Tamburo, 
    601 F.3d at
    699–
    700.
    11 The dissent here also cites Old Republic Insurance Co. v.
    Continental Motors, Inc., 
    877 F.3d 895
    , 902-03 (10th Cir. 2017),
    for the proposition that a "plaintiff's amended complaint is 'the
    operative one' for the purpose of analyzing" a defendant's motion
    to dismiss for lack of personal jurisdiction.      Old Republic is
    similar to Tamburo, as it also involved neither federal claims nor
    the application of Rule 4 to parties added after service of process
    had been effectuated.
    - 31 -
    Rule 4); SEC v. Ross, 
    504 F.3d 1130
    , 1138-40 (9th Cir. 2007)
    (holding that a court lacked jurisdiction over a defendant who was
    never served with or named as a party in the federal-law complaint,
    despite statute's nationwide service of process provision).12
    The Sixth Circuit opinion rests on a supposed anomaly
    resulting from our interpretation—that added parties and added
    claims are not subject to Rule 4's limitations.      The Sixth Circuit
    warned that reading Rule 4(k)(1)(A) as applying only to plaintiffs
    responsible for serving a summons risks "limitations on judicial
    power [being] one amended complaint—with potentially new claims
    and new plaintiffs—away from obsolescence."       Canaday, 9 F.4th at
    400; see also Molock, 952 F.3d at 309 (Silberman, J., dissenting)
    (suggesting that Rule 4(k) must be interpreted broadly to ensure
    that "litigants [cannot] easily sidestep the territorial limits on
    personal   jurisdiction   simply   by   adding   claims—or   by   adding
    plaintiffs, for that matter—after complying with Rule 4(k)(1)(A)
    in their first filing").
    12The opinion also relied on an article that states "courts
    regularly apply Rule 4(k)(1)(A) limitations to the claims
    appearing in amended complaints," but this proposition is also
    supported only by Tamburo. See A. Benjamin Spencer, Out of the
    Quandary: Personal Jurisdiction Over Absent Class Member Claims
    Explained, 39 REV. LITIG. 31, 43–44 (2019). Another statement cited
    in Canaday, see 9 F.4th at 400, that "Rule 4(k) remain[s] the
    operative constraint[] that district courts apply to . . . new
    claims by newly joined parties," cites the same article, which
    cites no support, see 39 REV. LITIG. at 44.
    - 32 -
    There is no anomaly.       As discussed above, Rule 4 is
    concerned with initial service, not jurisdictional limitations
    after service.   And the consequence is not that additional parties
    and claims can be added to escape jurisdictional limitations.          In
    both the case of added parties and claims, the court's jurisdiction
    is still subject to constitutional limitations—in the case of
    federal-law claims, the Fifth Amendment—and statutory limitations
    governing subject matter jurisdiction and venue.         See 7 Charles A.
    Wright, Arthur R. Miller & Adam N. Steinman, Federal Practice and
    Procedure § 1659 (3d ed.) ("[T]he statutory jurisdiction and venue
    requirements   are   fully   applicable   to   Federal   Rule   of   Civil
    Procedure 20 and may restrict the ability to join parties.")13          If
    there is any anomaly, it is the approach suggested by the Sixth
    Circuit—applying the Fourteenth Amendment to federal-law claims
    that are governed only by the Fifth Amendment.
    The Sixth Circuit also relied on the FLSA's failure to
    authorize nationwide service of process, urging that because the
    FLSA lacks a nationwide service of process provision, that left
    Rule 4(k)(1)(A) as the only basis for establishing jurisdiction.
    See Canaday, 9 F.4th at 396.     We agree that "a basis for service
    13Also, claims "radically different from those set out in the
    original pleading," may require courts to "direct personal service
    of the new pleading on the [defendant] pursuant to Rule 4." 4B
    Charles A. Wright, Arthur R. Miller & Adam N. Steinman, Federal
    Practice and Procedure § 1146 (4th ed.).
    - 33 -
    of a summons on the defendant is prerequisite to the exercise of
    personal jurisdiction," BNSF, 
    137 S. Ct. at
    1556 (citing Omni
    Capital, 
    484 U.S. at 104
    ), and 4(k)(1)(A) is the sole basis for
    service when nationwide service is not authorized. But the absence
    of a nationwide-service provision in the FLSA only requires resort
    to state law for service of process.      See United States v. Swiss
    Am. Bank, Ltd., 
    274 F.3d 610
    , 618 (1st Cir. 2001) ("[I]n federal
    question cases . . . a plaintiff need only show that the defendant
    has adequate contacts with the United States as a whole . . .
    [H]owever, the plaintiff must still ground its service of process
    in a federal statute or civil rule.")         It says nothing about
    whether   4(k)(1)(A)   constrains   the   court's   jurisdiction   once
    service is effectuated.14
    Finally, much of the Sixth Circuit opinion sought to
    distinguish FLSA collective actions and Rule 23 class actions,
    likening collective actions to the mass action in BMS.             See
    Canaday, 9 F.4th at 402–03.   We agree that FLSA collective actions
    and Rule 23 class actions are dissimilar in myriad ways.            The
    paramount similarity, and the only one that matters for purposes
    14 The Sixth Circuit contended that such an interpretation
    would render nationwide service of process provisions pointless.
    Canaday, 9 F.4th at 399 ("What indeed would be the point of these
    provisions if Civil Rule 4(k) already allowed jurisdiction and
    service?"). But our interpretation of Rule 4(k) does not allow
    nationwide service in all cases. Initial service must still rely
    on state law when there is no nationwide service provision.
    - 34 -
    of assessing the district court's jurisdiction here, is that the
    named plaintiff in both actions is the only party responsible for
    serving the summons, and thus the only party subject to Rule 4.15
    VI.
    Accordingly, we affirm the district court's denial of
    D&Z's motion to dismiss the nonresident opt-in plaintiffs.     The
    decision is
    Affirmed.   Costs to appellee.
    -Dissenting Opinion Follows-
    15 A separate Sixth Circuit opinion recently held that the
    personal jurisdiction inquiry in a Rule 23 class action is required
    only for a named plaintiff's claims because "a class action is
    formally one suit in which, as a practical matter, a defendant
    litigates against only the class representative," and "absent
    class members are not considered 'parties,' as a class
    representative is, for certain jurisdictional purposes."        See
    Lyngaas v. Curaden AG, 
    992 F.3d 412
    , 435 (6th Cir. 2021).
    - 35 -
    BARRON, Circuit Judge, dissenting.        The majority today
    decides a significant question of first impression in our Circuit
    about the meaning of Federal Rule of Civil Procedure 4(k)(1)(A).
    It does so in a manner that creates a direct conflict with the
    ruling of two circuits and that will have seemingly wide-ranging
    effects on a slew of cases that have nothing to do with the specific
    dispute at hand.     In my view, there is no reason for us to decide
    this question at this time, given the interlocutory posture of
    this appeal.     Thus, I write separately to explain why, for reasons
    independent of the merits of the majority's ruling, I dissent.
    I.
    Federal Rule of Civil Procedure 4(k)(1)(A) provides that
    a summons "establishes" personal jurisdiction over a defendant in
    a civil action that is brought in federal court if the defendant
    "is subject to the jurisdiction of a [state] court of general
    jurisdiction in the state where" the civil action commenced.         In
    response to relatively recent developments in the law that defines
    the limits that the Fourteenth Amendment's Due Process Clause
    places on the exercise of personal jurisdiction over a defendant
    in a civil action in state court, see Bristol-Meyers Squibb Co. v.
    Superior Court of California, San Francisco County, 
    137 S. Ct. 1773
       (2017),     some   commentators    have   called   for   amending
    Rule 4(k)(1)(A).     The commentators argue that, due to these recent
    developments, an amendment to the rule is necessary to ensure that
    - 36 -
    it does not become a bar to the beneficial aggregation of claims
    in federal court that it was not originally intended to be.    See
    Scott Dodson, Personal Jurisdiction and Aggregation, 
    113 Nw. U. L. Rev. 1
    , 37-40 (2018); see also Stephen E. Sachs, How Congress
    Should Fix Personal Jurisdiction, 
    108 Nw. U. L. Rev. 1301
    , 1316
    (2014).
    The commentators assert that for most of the rule's life
    Fourteenth Amendment-based due process limits on the exercise of
    personal jurisdiction in state court were not as strict as the
    Supreme Court of the United States has deemed them to be in recent
    rulings, such as Bristol-Meyers Squibb.   See Dodson, supra, at 37.
    The commentators also note that Fifth Amendment-based due process
    limits on the exercise of personal jurisdiction in federal court
    are not nearly as strict as the Fourteenth Amendment's parallel
    limits in state court have been held to be.       See A. Benjamin
    Spencer, The Territorial Reach of Federal Courts, 
    71 Fla. L. Rev. 979
    , 990-91 (2019).   The commentators thus contend that there is
    no good reason to saddle federal courts -- as Rule 4(k)(1)(A) now
    saddles them -- with the current limits on the exercise of personal
    jurisdiction that the federal Constitution imposes only on state
    courts.   See, e.g., the sources cited in Dodson, supra, at 36
    n.216.
    Nonetheless, no such amendment to Rule 4(k)(1)(A) has
    been made to this point, and defendants are invoking the rule with
    - 37 -
    seemingly greater frequency to request that federal courts dismiss
    claims based on limits on the exercise of personal jurisdiction
    imposed on state courts by the Fourteenth Amendment's Due Process
    Clause.    See, e.g., Lyngaas v. Curaden Ag, 
    992 F.3d 415
     (6th Cir.
    2021); Molock v. Whole Foods Mkt. Grp., Inc., 
    952 F.3d 293
     (D.C.
    Cir. 2020). Indeed, this case reflects the trend, as the defendant
    here -- Day & Zimmermann -- contends that Rule 4(k)(1)(A) bars the
    United States District Court for the District of Massachusetts
    from exercising personal jurisdiction over certain claims solely
    because of constraints that a state court in Massachusetts would
    face in exercising personal jurisdiction over those same claims by
    virtue    of   recent    Supreme   Court    precedent   interpreting      the
    Fourteenth Amendment's Due Process Clause.
    Specifically, Day & Zimmermann contends that, because of
    the    interaction    between    Rule   4(k)(1)(A)   and    the    Fourteenth
    Amendment-based due process limits on personal jurisdiction over
    a defendant in state court that were relatively recently set forth
    in Bristol-Myers Squibb, the District Court must dismiss the claims
    of certain of the individuals who have filed written consent forms
    that signal their intention to participate in the collective action
    that the named plaintiff here, John Waters, has initiated by the
    inclusion of a Fair Labor Standards Act (FLSA) collective action
    claim in his complaint pursuant to section 216(b) of the FLSA.              In
    that     complaint,     Waters   asserts,   alongside      his    own   solely
    - 38 -
    individual claim under the FLSA, an FLSA claim "on behalf of" what
    his complaint refers to as a "putative class" of certain former
    employees of Day & Zimmermann who are "similarly situated" to him.
    See 
    29 U.S.C. § 216
    (b).
    II.
    In rejecting Day & Zimmermann's contention that the
    District Court erred in denying the motion to dismiss the claims
    just described, the majority relies on the text and purposes of
    Rule 4(k)(1)(A). The majority contends based on these interpretive
    sources that the rule is best read to restrict the scope of the
    condition that it sets forth that makes it so that a summons
    "establishes" personal jurisdiction in federal court over the
    defendant who is served with it -- namely, the condition that the
    defendant "is subject to the jurisdiction of a [state] court of
    general   jurisdiction   in    the       state   where    the"   civil   action
    commenced.
    In the majority's view, Rule 4(k)(1)(A) must be read to
    subject   that   condition    to    an    implicit       time-of-service-based
    limitation on its scope.           The majority therefore rejects the
    contention -- pressed vigorously by Day & Zimmermann -- that the
    rule provides that the condition that it sets forth must be
    satisfied for the life of the suit.
    In other words, the majority embraces a reading of the
    rule in which that condition need be satisfied only at the time
    - 39 -
    that   the   summons   is   served.   For   this   reason,   the   majority
    concludes that the condition need not be satisfied, as Day &
    Zimmermann would have it, as to any claims and plaintiffs that are
    added after the summons has been served.
    The result is that, under the majority's reading of Rule
    4(k)(1)(A),    Fourteenth    Amendment-based    due    process   limits   on
    personal jurisdiction in state court -- including those set forth
    in Bristol-Myers Squibb -- can have no application to the claims
    of those individuals here who have filed written forms in which
    they have consented to participate in Waters's collective action
    pursuant to section 216(b) of the FLSA.        As the majority explains,
    such due process limits have no application to those claims by
    virtue of the Fourteenth Amendment itself, given that the suit is
    being brought in federal court.       And, as the majority emphasizes,
    those limits also have no application to those claims by virtue of
    Rule 4(k)(1)(A), because the individuals who filed the written
    forms in which they consented to participate in Waters's FLSA
    collective action did so only after Waters had served Day &
    Zimmermann with the summons.
    Thus, according to the majority, it follows that the
    only bar that could potentially prevent the District Court from
    exercising personal jurisdiction over Day & Zimmermann as to the
    claims at issue in this appeal is the bar that the Due Process
    Clause of the Fifth Amendment might impose.           But, as the majority
    - 40 -
    rightly concludes, Day & Zimmermann has made no argument that the
    Fifth Amendment's Due Process Clause does impose any such bar here.
    For that reason, the majority affirms the District Court's denial
    of the motion to dismiss that is before us in this appeal.
    III.
    The majority's time-of-service-based reading of Rule
    4(k)(1)(A) is internally coherent.      The text of that rule is at
    least arguably ambiguous as to whether the summons "establishes"
    personal jurisdiction over the defendant for the life of the suit
    only if that defendant "is" subject to the jurisdiction of the
    state court for the life of the suit or whether the summons
    "establishes" personal jurisdiction over the defendant for the
    life of the suit so long as that defendant "is" subject to the
    jurisdiction of a state court at the time that the summons is
    served.
    The majority's time-of-service-based reading of the rule
    also accords with the intuition that it would be odd for a rule
    that seeks only to describe the means for making service of process
    effective to make those means dependent on events that might occur
    after service has been made.     It is an arguable virtue of the
    majority's reading of the rule that one need only attend to what
    has occurred up until service has been completed to know whether
    such service has been effective.
    - 41 -
    The majority's reading of the rule also has going for it
    one more thing: it helps to ensure that the rule will not prove to
    be the seemingly unintended obstacle to the beneficial aggregation
    of claims in federal court that has provoked some commentators to
    call for its amendment.           That is because, under the majority's
    reading    of   the   rule,   a   plaintiff    may    ensure   the    beneficial
    aggregation of such claims in most cases merely by amending the
    complaint after the summons has been served to include any claims
    over which a state court would not be able to exercise personal
    jurisdiction.
    These features of the majority's reading of the rule do
    not, however, spare it from being controversial.               The reading is
    in apparent tension with the broader, life-of-the-suit reading of
    the   rule's    condition     that     would   appear     to   undergird     the
    commentators' calls for its amendment.               It would be strange for
    these commentators to have called for such an amendment if they in
    fact share the majority's view that the rule's deleterious effects
    on the beneficial aggregation of claims plainly can be overcome at
    present by a means as simple as the post-summons amendment of the
    complaint that was operative at the time that the summons was
    served.    See A. Benjamin Spencer, Out of the Quandary: Personal
    Jurisdiction over Absent Class Members Explained, 
    39 Rev. Litig. 31
    ,   43    (2019)     ("It       would   be   preposterous          to   suggest
    that . . . amended      complaints . . . may         evade   the   restrictions
    - 42 -
    applicable to claims contained within complaints served under Rule
    4, subject only to the limits of the Fifth Amendment's due process
    clause.     Were such the case, the ability to amend would provide a
    gaping    loophole   to    the   ordinary    territorial   restrictions   on
    federal court jurisdiction that Rule 4(k) imposes.").
    The majority's reading of Rule 4(k)(1)(A) also directly
    conflicts, as the majority itself acknowledges, with that of other
    circuits.    See Canaday v. Anthem Cos., 
    9 F.4th 392
    , 400 (6th Cir.
    2021) ("Even with amended complaints . . . the district court
    remains     constrained     by   Civil   Rule    4(k)'s -- and    the   host
    State's -- personal        jurisdictional      limitations.");    see   also
    Vallone v. CJS Solutions Grp., LLC, 
    9 F.4th 861
    , 865 (8th Cir.
    2021).     Nor am I aware of any other case in which any court
    (including our own) has ever read Rule 4(k)(1)(A) in the narrow,
    time-of-service-limited way that the majority reads it.
    Indeed, the common (if, perhaps unreflective) practice
    of federal courts under this rule appears, as best I can tell, to
    have been to apply Fourteenth Amendment-based (rather than Fifth
    Amendment-based)     due    process   limits    on   personal   jurisdiction
    throughout a suit's duration, and so even as to later-added claims
    and plaintiffs. See, e.g., Old Republic Ins. Co. v. Cont'l Motors,
    Inc., 
    877 F.3d 895
    , 902-03 (10th Cir. 2017) (noting that the
    plaintiff's amended complaint is "the operative one" for the
    purpose of analyzing a Rule 12(b)(2) motion to dismiss for lack of
    - 43 -
    personal jurisdiction); see also Spencer, Out of the Quandary,
    supra, at 43 ("There is no question that -- notwithstanding that
    such amended complaints are not served with a summons under Rule
    4 -- new claims appearing in amended complaints must satisfy the
    jurisdictional constraints imposed by Rule 4(k); courts regularly
    apply Rule 4(k)(1)(A) limitations to the claims appearing in
    amended complaints.").16   Thus, it would appear that, given the way
    that the majority now reads the rule, federal courts in our circuit
    will have to change how they have been doing things in many cases,
    and in all cases that involve state law claims.      For, under the
    majority's reading, they will have to assess personal jurisdiction
    in those cases with exclusive reference to Fifth Amendment-based
    16   The majority appears to suggest that even if Rule
    4(k)(1)(A) applies to state law claims added post-summons, it does
    not apply to parties asserting federal claims post-summons. Maj.
    Op. at 31 n.10. But, nothing in the text of the rule distinguishes
    between the rule's application to state law claims and its
    application to federal ones, even though the rule plainly applies
    to federal claims generally, see Walden v. Fiore, 
    571 U.S. 277
    ,
    283 (2014) (applying Rule 4(k)(1)(A) to a federal law claim), and
    even though other parts of Rule 4(k) do expressly distinguish
    between state and federal claims, see Fed. R. Civ. P. 4(k)(2)
    (drawing that very distinction by way of reference to "a claim
    that arises under federal law"). Nor does anything in the text of
    the rule distinguish between the rule's application to claims and
    its application to parties. Thus, it would appear to be the case
    that however the rule applies to later-added state law claims must
    be how it applies to later-added parties asserting federal claims.
    I add only that the rule's failure to draw a distinction between
    state and federal claims is precisely what has motivated
    commentators to recommend that the rule be amended to ensure that
    federal claims (including, it seems, ones brought by later-added
    parties) are not subject to the rule in the same way that state
    law claims are. See Dodson, supra, at 37-40.
    - 44 -
    due process limits (and thus to work their way through all the
    legal complexity that may arise from their doing so in cases
    involving state law claims) despite their seeming common practice
    of not using that lens except in certain classes of cases that
    involve federal claims,       see Fed. R. Civ. P. 4(k)(1)(C);            id.
    4(k)(2), in which the degree of legal complexity that then arises
    from using that same lens is much less.
    IV.
    In my view, there is no reason to decide in this case
    whether the majority is right to read Rule 4(k)(1)(A) to be subject
    to the implicit time-of-service limitation that it discerns on the
    scope of the condition that the rule sets forth.                 Given the
    embryonic state of the FLSA collective action that is before us
    and the interlocutory nature of this appeal, I would let the suit
    proceed apace in the District Court rather than attempt to resolve
    on   interlocutory   review   this    substantial    question    of    first
    impression   in    our   Circuit     about   the    best   way    to   read
    Rule 4(k)(1)(A).     In fact, it seems to me that there is special
    reason to follow this more restrained course here, because the
    resolution of the question that the majority chooses to decide in
    this case's preliminary posture will be binding in our Circuit not
    only in cases that concern collective actions under the FLSA but
    also in a whole range of cases that also implicate Rule 4(k)(1)(A)
    but that have nothing to do with FLSA collective actions at all.
    - 45 -
    I note that the more cautious approach that I favor,
    which would cause me to dismiss this interlocutory appeal, accords
    with our general reluctance to hear appeals from denials of motions
    to dismiss precisely because such appeals necessarily come to us
    on an interlocutory basis.    See Caraballo-Seda v. Municipality of
    Hormigueros, 
    395 F.3d 7
    , 8 (1st Cir. 2005) (acknowledging "our
    general rule prohibiting interlocutory appeals from the denial of
    a motion to dismiss").    Nor do I see a reason to deviate from this
    tried-and-true stance by making a case-specific exception to it
    here, even if there might be good reason to make such an exception
    in some cases that involve requests to appeal from denials of
    motions to dismiss that are made in connection with collective
    actions that are brought under section 216(b) of the FLSA.
    The underlying (and unsuccessful) motion to dismiss that
    is at issue here was made before the named plaintiff who filed the
    complaint asserting the FLSA collective action claim, Waters, has
    even moved to certify the putative class of "similarly situated"
    employees on whose behalf he seeks to sue in bringing that claim.
    See 
    29 U.S.C. § 216
    (b).    Thus, as Waters pointed out in opposing
    interlocutory review of the denial of that motion here, still more
    opt-ins may consent to participate in the collective action that
    is at issue even after a ruling on the merits of this appeal.   Nor
    do we know for certain at this juncture -- as we would if we waited
    for a motion to certify to be filed -- that Waters will seek to
    - 46 -
    bring a collective FLSA action on behalf of every present opt-in,
    let alone on behalf of each of those opt-ins who would be permitted
    to sue under the majority's construction of Rule 4(k)(1)(A).         Cf.
    Molock, 952 F.3d at 298-99 ("[P]rior to . . . certification, the
    potential [collective action] and their potential claims are just
    that: potentials.").    And, of course, it is up to Waters in the
    first instance whether any individual who might wish to opt in and
    participate in the collective action may do so, precisely because
    he is bringing it.
    Reinforcing the reason to adhere in this case (given its
    nascent nature) to our usual unwillingness to resolve an appeal
    from a denial of a motion to dismiss is the fact that Day &
    Zimmermann has made little more than a conclusory showing about
    the need for us to weigh in now on the District Court's ability to
    exercise personal jurisdiction over it as to the claims of members
    of what at this point is only a "putative" class of claimants.
    That Day & Zimmermann has not made a substantial showing of an
    unusual need for resolution of that question this early in this
    case is especially significant because it is not as if Day &
    Zimmermann is presently at risk of being held liable to any of the
    so-called opt-ins who might end up being in that still, as-yet-
    defined class.
    If   a   default   judgment   were   entered   against   Day   &
    Zimmermann at this point in the case, I do not see how any of those
    - 47 -
    individuals who thus far have filed written consent forms to
    participate in Waters's collective action under the FLSA could
    benefit from that judgment any more than they could if they had
    not   filed    such   forms.            That   is    precisely     because    the     named
    plaintiff who is bringing the collective action under the FLSA,
    Waters, has not yet moved for certification of a collective action
    on their behalf -- or, for that matter, on behalf of anyone.                            Cf.
    Rodriguez v. Almighty Cleaning, Inc., 
    784 F. Supp. 2d 114
    , 129
    (E.D.N.Y. 2011) (granting a motion for certification of an FLSA
    collective     action        simultaneously          with   a     motion    for    default
    judgment).
    Thus, while I recognize that an earlier panel of our
    Court granted the petition for certification of the interlocutory
    appeal   pursuant       to    
    28 U.S.C. § 1292
    (b),           see   Waters v.     Day   &
    Zimmermann NPS, Inc., No. 20-1831 (1st Cir. Oct. 14, 2020), I am
    convinced -- now        that       we    have       had   full    briefing     and    oral
    argument as      that        panel      did     not -- that        the     petition     was
    improvidently granted.             See Caraballo-Seda, 
    395 F.3d at 9
    .                 I am
    aware in so concluding of the out-of-circuit precedent that has
    permitted the interlocutory review of the merits of a ruling on a
    motion to dismiss the claims of individuals who had opted in to a
    named plaintiff's collective action claim under the FLSA.                             But,
    the cases that have permitted such an appeal were ones not only in
    which that appeal was from a grant of the motion to dismiss but
    - 48 -
    also in which the appeal was from a ruling on a motion to dismiss
    that was made at the time of (or in the wake of) a motion to
    certify a class of similarly situated persons on behalf of whom
    the named plaintiff was bringing the collective action under the
    FLSA.     See Canaday, 9 F.4th at 395; see also Vallone v. CJS
    Solutions Grp., LLC, 
    9 F.4th 861
    , 864 (8th Cir. 2021) (involving
    appellate review of a district court's order limiting an FLSA
    collective action to "employees 'who engaged in out-of-town travel
    to or from a Minnesota jobsite for [the defendant] or who resided
    in Minnesota'").   I am not aware of any precedent prior to this
    case in which a court has permitted interlocutory review of a
    denial of a motion to dismiss such opt-in claims in an FLSA
    collective action, let alone any such precedent in a case of that
    sort in which the denial of the motion to dismiss preceded -- as
    it does here -- a motion to certify the class of "similarly
    situated" persons on whose behalf the named plaintiff is bringing
    the collective action under the FLSA.17
    17   I note that, in other cases in which, like here, the
    named plaintiff had made no motion to certify the class of
    "similarly situated" individuals on whose behalf the FLSA
    collective action would be brought, other district courts have
    denied motions to certify for interlocutory appeal under 
    28 U.S.C. § 1292
    (b) the district court's order denying a Fed. R. Civ. P.
    12(b)(2) motion to dismiss the claims of opt-ins. See Murphy v.
    Labor Source, LLC, No. 19-cv-1929, 
    2021 WL 527932
     (D. Minn. Feb.
    12, 2021); Seiffert v. Qwest Corp., No. CV-18-70-GF-BMM, 
    2019 WL 859045
     (D. Mont. Feb 22, 2019).
    - 49 -
    Accordingly, I would dismiss this appeal.       By doing so,
    we   would   be   following   our   usual    wait-and-see   approach   when
    confronted with a request to decide an appeal from a denial of a
    motion to dismiss, and, by doing so, we also would be ensuring
    that we would not be deciding a major question about the meaning
    of the Federal Rules of Civil Procedure in a case in which it may
    turn out not to be necessary for us to decide that question at
    all.18
    18  The majority does undertake an extensive analysis of
    whether the opt-ins in an FLSA collective action are party-
    plaintiffs who can appeal a ruling denying certification of a
    collective action on their behalf. See Campbell v. City of Los
    Angeles, 
    903 F.3d 1090
    , 1104-06 (9th Cir. 2018); Mickles v. Country
    Club Inc., 
    887 F.3d 1270
    , 1278 (11th Cir. 2018). But, I do not
    see how those precedents are relevant to the question that is my
    concern, which pertains to whether we should be entertaining this
    interlocutory appeal when no motion for certification has even
    been filed, let alone denied. I do also note that even if the
    majority is right to endorse the precedents that it relies on about
    the party-plaintiff status of opt-ins, the wait-and-see approach
    that I favor avoids the oddity of resolving on appeal the merits
    of a motion to dismiss claims that belong to individuals who are
    not even listed in the case's caption as parties to the appeal.
    My concern with our choosing to resolve such a motion in this odd
    posture is heightened by the fact that nothing in Day &
    Zimmermann's briefing to this Court indicates that Day & Zimmermann
    is seeking to dismiss Waters's collective action claim itself (even
    in part), as the briefing by Day & Zimmermann advances arguments
    for dismissing only the claims of the individual opt-ins, none of
    which are Waters's claims alone. Cf. Molock, 952 F.3d at 300. In
    any event, insofar as Day & Zimmermann could be understood to be
    seeking to dismiss not those claims directly but only Waters's
    collective action claim insofar as it is brought on the opt-ins'
    behalf, the appeal remains interlocutory and thus still should be
    dismissed for all the reasons that I have given.
    - 50 -