# United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued November 8, 2022 Decided July 18, 2023

No. 22

- 7033

I SAAC H ARRIS , ET AL ., A PPELLEES

v.

M EDICAL T RANSPORTATION M ANAGEMENT , I NC ., A PPELLANT

v.

S TAR T RANSPORTATION LLC, ET AL ., A PPELLEES

Appeal from the United States District Court for the District of Columbia (No. 1:17

- cv

- 01371)

Jean

- Claude André argued the cause for appellant. With him on the briefs were John J. Hathway

, Darci F. Madden , and William F. Ryan

. Jennifer B. Dickey

, Gilbert C. Dickey

, and Jessica L. O ’ Brien were on the brief for amicus curiae the Chamber of Commerce of the United States of America in support of appellant.2
William M. Jay and David J. Zimmer were on the brief for amicus curiae Prof. Joan Steinman in support of appellant.

Michael T. Kirkpatrick argued the cause for appellees. With him on the brief were Josep h M. Sellers

, Harini Srinivasan
, and Wendy Liu

. Robert H. Klonoff

, Elizabeth J. Cabraser

, and Samuel Issacharoff , pro se, were on the brief for amici curiae Robert H. Klonoff, Elizabeth J. Cabraser, and Samuel Issacharoff, in support of appellees as to Ru le 23(c)(4) standard.

Before: M ILLETT and C HILDS , Circuit Judges , and R OGERS , Senior Circuit Judge

. Opinion for the Court filed by Circuit Judge M ILLETT

.

M ILLETT , Circuit Judge : Isaac Harris, Darnell Frye, and Leo Franklin work as non

- emergency medical transportation drivers

. In July 2017, they brought a putative class action and Fair Labor Standards Act collective action against Medical Transportation Management, Inc. (“MTM”) . Their complaint alleged that MTM is their employer an d had failed to pay them and its other drivers their full wages as required by both federal and District of Columbia law

. MTM now appeals the district court’s certification of an

“ issue class ” under Federal Rule of Civil Procedure 23(c)(4)

, and its denial of MTM’s motion to decertify plaintiffs’ F air Labor Standards Act collective action

. W e remand the district
court ’s certification of the issue class because the court failed to ensure that it satisf ies the class

- action criteria specified in Rule 23 (a) and (b) . We decline to exercise pendent appellate jurisdiction to review the district court’s separate decision on the Fair Labor Standards Act collective action.3

I

A

Federal Rule of Civil Procedure 23 governs class action litigation in the federal courts. Rule 23(a) sets out the threshold criteria for eligibility as a class action, which are that (1) the proposed class be “so numerous that joinder of all members is im practicable”

— the numerosity requirement; (2) class members’ claims share common questions of law or fact

— the commonality requirement; (3) the claims or defenses of the named representative parties be typical of all class members

— the typicality requirement ; and (4) the representative parties be capable of providing adequate representation to the whole class

— the adequacy of representation requirement. F ED

. R. C IV

. P . 23(a) (1)

– (4)

. In addition to meeting those four prerequisites, Rule 23(b) provides that a proposed class must also qualify as one of three specified “types of class actions.” F ED

. R. C IV

. P . 23(b)(1)

– (3) ( formatting modified ) ; see A mchem Prod s ., Inc. v. Windsor

, 521 U.S. 591, 614 (1997).

Rule 23(b)(1) def ines the first type of class action as applying when there are multiple claims arising out of the same subject matter and the prosecution of separate actions by or against individual class members “would create a risk of” either “inconsistent or varying” judgments establishing “incompatible standards of conduct” for the party opposing the class. F ED

. R. C IV

. P . 23(b)(1). A class can also proceed under Rule 23(b)(1) if resolution of individual class members’ claims would, “as a practical matter” dispose of the inte rests of the

non

- party members of the class, or “would substantially impair or impede their ability to protect their interests [

. ] ” Id

.4

R

ule 23(b)(2) identifies a se cond type of class action

, which may be maintained if the party opposing the class “has acted or refused to act on grounds that apply generally to the class,” so that “final injunctive relief or corresponding declaratory relief” would be appropriate to resolve all class claims. F ED

. R. C IV

. P . 23(b)(2).

F inally, a Rule 23(b)(3) class action can be maintained whe n “ questions of law or fact common to class members predominate over any questions affecting only individual members, ” and “ a class action is superior to other available methods for fairly and effic iently adjudicating the controversy .” F ED

. R. C IV

. P . 23(b)(3).

Other parts of Rule 23 set out the procedural and operational requirements of a class action

. For example, upon certifying a class action, the district court “must define the class and th e class claims, issues, or defenses [ .] ” F ED

. R. C IV

. P

. 23(c)(1)(B). Also, f or any class certified under Rule 23(b)(3)

, the district court is required to provide class members “ the best notice that is practicable under the circumstances, including individual notice to all members who can be identified through reasonable effort.” F ED

. R. C IV

. P . 23(c)(2)(B). The notice requires , among other things, a statement informing class

me mbers of their right to opt out of the action and thereby to maintain their ability to pursue any action individually

. F ED

. R. C IV

. P . 23(c)(2)(B) (v) ( “ T he notice must clearly and concisely state in plain, easily understood language * * * that the court w ill exclude from the class any member who requests exclusion[.]” ) ; s ee also , e.g. , F ED

. R. C IV

. P . 23 (e) , (g)

. In addition to all of those mandatory class

- action requirements, Rule 23 has permissive provision s concerning the district court’s management of class litigation

. This case concerns the application of one of them, Rule 23(c)(4), which5
provides: “When appropriate, an action may be brought or maintained as a class action with respect to particular iss ues.” F ED

. R. C IV

. P . 23(c)(4).

Th is appeal asks us to decide what role Rule 23(c)(4) plays in class certificatio n decisions and, in particular, whether a Rule 23(c)(4) issue class must also meet the Rule 23 (a) and (b) class action requirements

.

B

1

Non

- emergency medical transportation services are used by individuals who receive Medicaid and lack transportation for their medical appointments. MTM contracts with t he District of Columbia to provide District residents with such services. To fulfill t hose contracts, MTM engages dozens of subcontractors

. Plaintiffs Harris, Frye, and Franklin (collectively

,

“ Drivers ”) are non

- emergency medical transportation drivers in the District of Columbia. The Drivers allege that while t he y and hundreds of other drivers w ere working for MTM and its subcontractors, MTM failed to pay their legally mandated wages under federal and District law. They allege that t he y and the other driv ers routinely started work between 5:00 a.m. and 7:00 a.m., and w orked until between 5:00 p.m. and 8:00 p.m

. Nevertheless

, the Drivers were paid a flat rate for driver services that “regularly fell below ” the legally required

“ minimum wage and the living wage rates” and omitted overtime wages

. Compl. at 9

– 10, J.A. 40

– 41

.

The Drivers brought suit against MTM under the F air Labor Standards Act, 29 U.S.C. § 201 et seq. (“FLSA”), under6
District of Columbia wage

- and

- hour laws, see D.C. Code § 32

- 1001 (Minimum Wage Act); id. § 2

- 220.01 et seq. (Living Wage Act); id. § 32

- 1302 (Wage Payment and Collection Law)

, and for common

- law breach of contract. As required to state a claim under th o se causes of action, the Drivers ’ complaint alleged that MTM was an employer of the D rivers under federal law and a general contractor under D istrict law

.

Whether MTM is either an employer or a general contractor with respect to the Drivers is a threshold question of liability for MTM

. If MTM is deemed the employe r of the plaintiffs, or a joint employer with its subc ontractors, MTM may be held liable under both the FLSA and District law

. And i f it is a “general contractor

, ” that status would separately subject it to strict liability for violations of District law by its subcontractors. See Harris v. Medical Transp. Mgmt., Inc. , 300 F. Supp. 3d 234, 246 (D.D.C. 2018) (“ Harris I ”). But if, as MTM argues , it n either employed nor acted as a general
contrac tor in relation to the Drivers

, it cannot be liable for any underpayment of wages . In that case, the subcontractors MTM engaged and to which the Drivers directly reported would be the only proper defendants

.

2

MTM moved to dismiss the complain t in its e ntirety

. The district court granted the motion as to the Drivers’ commo n

law breach of contract claim, but denied it as to the Drivers’ claims under federal and District statutory law. Harris I , 300 F. Supp. 3d at 23 7

. Then the district court granted the Drivers’ motion for conditional certification of an FLSA collective action , approved the Drivers’ proposed collective action notice, and equitably tolled the limitation s period for members of the collective action

. See Harris v . Medical Transp. Mgmt., Inc.

, 317 F. Supp. 3d 421, 423

– 424 (D.D.C. 2018) (“ Harris II ”).7

The Drivers subsequently filed a motion to certify a class action under Rule 23(b)(3) for the non

- FLSA claims

. T he district court denied the motion

. Harris v. Medic al Transp. Mgmt., Inc.
, No. 17 Civ. 01371, 2020 WL 5702085 (D.D.C. Sept. 24, 2020) (“ Harris III ”). The district court found that the proposed class action met the requirements of Rule 23(a), and the superiority requirement of Rule 23(b)(3)

— that is, it found that a class action would be “superior to other available methods for fairly and effectively ad judicating the controversy [,] ” F ED

. R. C IV

. P . 23(b)(3)

. Harris III
, 2020 WL 5702085
, at *4

– 7

. T he district court also found that the question of whether MTM was , with its subcontractors, a joint employer of the putative class members “meets the predomi nance requirement of Rule 23(b)(3) ” because evidence common to the class would be used to resolve it. Id. at *9

.

But the district court held that individualized evidence would be required to assess whether MTM’s payment system was responsible for the underpayment of wages, given “numerous metrics that would be relevant to assessing MTM’s liability as to each class member.” Harris III , 2020 WL 5702085, at *9. Accordingly, because the evidence common to the putative class as a whole did not predominate over such individual considerations, the district court declined to certify a class under Rule 23(b)(3). Id. at *12

. The district court also d enied without prejudice the Drivers’ motion in the alternative to certify a n is sue class under Rule 23(c)(4 ). Id. at *13

. Following supplemental briefing, the district court granted in part the Drivers’ renewed motion to certify issue class es under Rule 23(c)(4). Harris v. Medical Transp. Mgmt., Inc.

, No. 17 Civ. 01371, 2021 WL 3472381

, at *1 (D.D.C. Aug. 6, 2021) (“ Harris IV ”)

. The district court certified one issue class, defin ing th at class as encompassing the two questions of (1)8

w hether MTM is a joint employer of the putative class members ; and (2) w hether MTM is a general contractor under D.C. law , and thereby strictly liable for any wage law violations committed by its subcontractors. Id. at *9. The district court reas oned that certifying an issue class for those two issues would “materially advance the litigation” because, if MTM is neither a joint employer nor a general contractor, it will not be liable in the lawsuit for any claims

. Id

. (citation omitted). But if MTM meets one or both of those definitions, the Drivers will have established a critical co mponent of their

case

. Id. ; see also Harris III , 2020 WL 5702085, at *6. The district court also noted that the Drivers would rely on evidence common to all proposed class members to attempt to prove that MTM is a joint employer or a general contractor. Harris IV
, 2021 WL 3472381
, at *9

. In the same opinion, the district court denied MTM’s motion to decertify the plaintiffs’ FLSA collective action . A collective action under the FLSA requires the members to be “similarly situated.” 29 U.S.C. § 216. That term is not defined by the FLSA . Because our c ircuit has not yet established a standard for “similarly situate d,” t he district court applied a test from the Second and Ninth Circuits, which asks whether “party plaintiffs [are] alike with regard to some material aspect of their litigation.” Harris IV , 2021 WL 3472381
, at *3 (quoting Campbell v. City of Los Angeles , 903 F.3d 1090, 1113

– 1114 ( 9th Cir. 2018)) (emphasis in Campbell ; alteration in Harris ) ; see also Scott v. Chipotle Mexican Grill, Inc. , 954 F.3d 502, 515

– 522 (2d Cir. 2020), cert. dismissed

, 142 S. Ct. 639 (2021). The district court then determined that the collective members were similarly situated with respect to the question of whether MTM is their joint employer and, because that inquiry is a material aspect of the litigation, the court denied MTM’s motion to decertify the collective action. Harris IV , 2021 WL 3472381, at * 6

– 7

.9

3

After filing a petition for leave to file an interlocutory appeal under Rule 23(f) in this court, see In re Medical Transp. Mgmt., Inc. , No. 21

- 8006, MTM also moved the district court to certify the FLSA decision for interlocutory review under 28 U.S.C. § 1292(b) and to stay proceedings pending the appeal

. The district court denied both motion s

. Harris v. Med ical Transp

. Mgmt., Inc. , No. 17 Civ. 0 1371, 2021 WL 5446829, at *1 (D.D.C. Nov. 22, 2021) (“ Harris V ”).

This court subsequently granted MTM’s petition to file an appeal of the class certification decision and directed the parties to address whether we should also exercise pendent appellate jurisdiction over the FLSA decision. In re Medical Transp. Mgmt., In c. , No. 21

- 8006, 2022 WL 829169, at *1 (D.C. Cir. March 17, 2022).

II

The district court ha d jurisdiction over this action under 28 U.S.C. § 1331 and § 1367. We have jurisdiction to consider MTM’s interlocutory appeal of the district court’s class
cert ification order under 28 U.S.C. § 1292(e)

. W e decline

, though, to exercise pendent appellate jurisdiction to review the district court’s denial of FLSA decertification.

III

While interlocutory appeals are generally dis favored

, Rule 23(f) provides that “[a] court of appeals may permit an appeal from an order granting or denying class

- action certification ” under Rule 23. F ED

. R. C IV

. P. 23(f). An appeal will generally be warranted “ when: (1) ‘ there is a death

- knell situation for10

either th e plaintiff or defendant[,] ’ in that the class

- certification decision will effectively end the party ’ s ability to litigate; (2)

‘ the certification decision presents an unsettled and fundamental issue of law relating to class actions, important both to the specific litigation and generally, that is likely to evade end

- of

- the

- case review; ’ or (3) ‘ the district court ’ s class certification decision is manifestly erroneous. ’ ” In re White

, 64 F. 4th 302, 307 (D.C. Cir. 2023) (alteration in original) (quoting In re Lorazepam & Clorazepate Antitrust Litig. , 289 F.3d 98 , 105 (D.C. Cir. 2002) )

. Applying those factors, we hold that interlocutory review of the class certification decision is appropriate in this case. T he distric t court’s decision to certify an issue class “‘presents an unsettled and fundamental issue of law relating to class actions’ that is ‘ important ’ and ‘likely to evade end

- of

- the

- case review [

. ] ’” In re Medical Transp. Mgmt., Inc ., 2022 WL 829169, at *1 (quoting Lorazepam , 289 F.3d at 99

– 100). More specifically, the question of under what conditions a Rule 23(c)(4) “issue class” can be certified when no lawsuit or cause of action has been certified as a class is an “unsettled and fundamental issue of law relating to class actions , important both to the specific litigation and generally [

. ] ” S ee Lorazepam
, 289 F.3d at 105. This court has not yet addressed that question

. Cf. In re Johnson , 760 F.3d 66, 75 (D.C. Cir. 2014) (recognizing “a controversy over the proper use of issue classes

, ” but declining to review “the district court’s determination of how best to manage the issues before it” because “the appropriate use of an issue class was not raised or brief ed ”) ; In re Brewer , 863 F.3d 86 1, 875

– 876 (D.C. Cir. 2017) (finding no “manifest error” in district court’s failure to “certif[y] a Rule 23(c)(4) issue class on liability alone”).

O ther c ircuits have applied Rule 23(c)(4) in a variety of
ways

. See, e.g.
, In re Nassau County Strip Se arch Cases , 46111
F.3d 219, 226

– 227 (2d Cir. 2006) ( “[A] cour t may employ subsection (c)(4) to certify a class as to liability regardless of whether the claim as a whole satisfies Rule 23(b)(3) ’ s predominance requirement

. ”) ; Russell v. Educational Comm’n for Foreign Med. Graduates , 15 F. 4th 259, 269

– 270 (3d Cir. 2021) ( “[D] istrict courts may certify ‘ particular issues ’ for class treatment even if those issues, once resolved, do not resolve a defendant ’ s liability, provided that such certification

substantially facilitates the resolution of the civil dispute, preserves the parties’ procedural and substantive rights and responsibilities, and respects the constitutional and statutory rights of all class member [s] and defendants

. ”), cert. denied

, 142 S. Ct. 2706 (2022) ; Gunnells v. Healthplan Servs., Inc.

, 348 F.3d 417, 438

– 446 ( 4th Cir. 2003) ; id. at 441 (“ [S] ubsection 23(c)(4) should be used to separate one or more claims that are appropriate for class treatment, provided that within that claim or claim s (rather than within the entire lawsuit as a whole), the predominance and all other necessary requirements of subsections (a) and (b) of Rule 23 are met

. ”) (internal quotation marks omitted) ; Castano v. Am erican Tobacco Co. , 84 F.3d 734, 745 n.21 (5th Cir. 1996) (“ The proper interpretation of the interaction between subdivisions (b)(3) and (c)(4) is that a cause of action, as a whole, must satisfy the predominance requirement of (b)(3) and that (c)(4) is a housekeeping rule that allows courts to sever the common issues for a class tri al.”) ; Martin v. Behr Dayton Thermal Prod s . LLC , 896 F.3d 405, 413 (6th Cir. 2018) (“ Rule 23(c)(4) contemplates using issue certification to retain a case ’ s class character where common questions predominate within certain issues and where class treatment of those issues is the superior method of resolution .”) ; McReynolds v. Merrill Lynch, Pierce, Fenner & Smith, Inc. , 672 F.3d 482, 491

– 492 (7th Cir. 2012) (Rule 23(c)(4) issue class could be used to resolve only a disparate impact issue ) ; cf. Valentino v. Carter

- Wallace, Inc.

, 97 F.3d 1227, 1234 (9th Cir. 1996) (“ Even if the common12
questions do not predominate over the individual questions so that class certification of the entire action is warranted, Rule 23 authorizes the district court in appropriate cases to isolate the common issues under Rule 23(c)(4)(A) and proceed with class treatment of these particular issues. ”) (citing the earlier version of Rule 23(c)(4)). 1

Given the variety of approaches and the frequency with which the certification of issue classes arises, the propriety of the court’s issue

- class certification decision in this case presents “an important, recurring, and unsettled question of class action l aw.” See In re White , 64 F.4th at 310

. In addition, the questi on of when issue classes can be certified is likely to evade end

- of

- the

- case review

. That would happen, f or example, if the district court holds that MTM is

n either an employer n or a general contractor

, resolving this

case on the merits in MTM’s favor

. MTM m ight lack any remaining injury from the class certification decision at that point and so be unable or unlikely to seek review of the question

. Likewise, even if MTM is found to b e a joint employer or a general contractor

, it could prevail on the merits, resolving th e suit in its favor

. That too would make end

- of

case review unlikely.

For those reasons, we find it appropriate to exercise our discretion to entertain this interlo cutory appeal. See In re White , 64 F .4 th at 312. We review the class certification

1 As originally adopted, Rule 23(c)(4) read: “When appropriate (A) an action may be brought or maintained as a class action with respect to particular issues, or (B) a class may be divided into subclasses and each subclass treated as a class, and the provisi ons of this rule shall then be construed and applied accordingly.” F ED

. R. C IV

. P. 23(c)(4) (1966). After the 2007 amendments to Rule 23, the former Rule 23(c)(4)(B) is now Rule 23(c)(5).13

decision for an abuse of discretion. Califano v. Yamasaki , 442 U.S. 682, 703 (1979); Garcia v. Johanns , 444 F.3d 625, 631 (D.C. Cir. 2006). The district court’s interpretation of Rule 23 is a question of law that we review de novo

. See Orozco v. Garland , 60 F.4 th 684, 688 (D.C. Cir. 2023)

.

I V

We hold that the district court abused its discretion by certifying th e issue cla s s under Rule 23(c)(4) without first determining that Rule 23’s requirements for class certification
were met as to the issue class

. Rule 23 (c)(4) does not create a fourth category of class action beyond those specified in Rule 23(b). Instead, Rule 23(c)(4) el ucidates what district courts can do as part of managing Rule 23

- qualifying class actions.

As a result, a ny “issue class” under Rule 23(c)(4) must also meet the threshold requirements of Rule 23(a) and be maintainable under one of the c lass action types laid out in Rule 23(b)

. B ecause the district court here did not explain how the issue class it certified me t the requirements of Rule 23(a) and (b)

— with (b)(3) being the relevant type of class action in this

case

— we remand for further co nsideration.

A

Under the plain text of Rule 23, a ll certified class es must meet both the threshold requirements of Rule 23(a) and be maintainable under one of Rule 23(b)’s categories

. There is no freestanding class to be certified under Rule 23(c)(4).

To start, courts repeatedly have held that the district court must apply the requirements of Rule 23(a) and Rule 23(b) when certify ing a ny class. Those criteria are fundamental prerequisites to the existence of a class action. See F ED

. R. C IV

.14

P. 23(a) (describing “prerequisites” to class action); F ED

. R. C IV

. P. 23(b)(3) (requiring district court to “find[]” predominance and superiority); see al so , e.g. , Tyson Foods, Inc. v. Bouaphakeo , 577 U.S. 442, 453 (2016 ) ( Rule 23(b)(3) “requires that, before a class is certified under that subsection, a district court” make the required findings of predominance and superiority) ; In re White , 64 F.4 th at 313 (abuse of discretion not to apply Rule 23(a) factors); Wang v. Chinese Daily News, Inc. , 737 F.3d 538, 542 (9th Cir. 2013) (“A party seeking class certification must satisfy the requirements of Federal Rule of Civil Procedure 23(a) and the requirem ents of at least one of the categories under Rule 23(b).”); Gariety v. Grant Thornton, LLP , 368 F.3d 356, 362 (4th Cir. 2004) (“A district court may, in its discretion, order that an action proceed as a class action only if it finds that the requirements o f Federal Rule of Civil Procedure 23 have been satisfied.”) ; In re LifeUSA Holding Inc. , 242 F.3d 136, 143 (3d Cir. 2001) (“In order to be certified, a class must satisfy the four requirements of Rule 23(a) of the Federal Rules of Civil Procedure[.] * * * If these Rule 23(a) requirements are satisfied, the court must also find that the class is maintainable under Rule 23(b)(1), (2), or (3).”).

Rule 23(c)(4) does not give the district court a pass on th o se preconditions

. To the contrary, Rule 23(c)(4) say s upfront that an issue class may only be certified “[w]hen appropriate [

. ] ” F ED

. R. C IV

. P . 23(c)(4). Th at appropriateness inquiry naturally includes the elementary class

- action requirements of Rule s 23(a) and (b)

, which ensure that class litigation is f air, suitable

, and advisabl e

— that is, appropriate

. What is more, Rule 23(c)(4)’s use of the phrase “maintained as a class action” echoes Rule 23(b)’s language that “[a] class action may be maintained” if , and only if, Rule 23(a) is satisfied and if the proposed class falls into one of Rule15
23(b)’s types. Plus, Rule 23(c)(4) continues (and ends) by stating that “an action may be brought or maintained as a class action with respect to particular issues.” F ED

. R. C IV

. P

. 23(c)(4) (emphasis added). T hat textually directs the court right back to the requirements of Rule 23(a) and Rule 23(b) that set out the basic ground rules for bringing or maintaining a class action

. See also Russell , 15 F.4th at 262 ; 2 N EWBERG & R

UBENSTEIN ON C LASS A CTIONS § 4:92 (6th ed.) (“[T]he proponent of an issue class

— like the proponent of any other class action

— must demonstrate that the proposed issue class meets all of the requirements of Rule 23(a) and fits into one of the cate gories of Rule 23(b)[.]”).

Finally, t he structure of Rule 23 in general and Rule 23(c) in particular counsel against finding a standalone Rule 23(c)(4) class. Rule 23 (c)(2) spells out the notice requirements for each variant of a Rule 23(b) class

. But it is silent about any notice provisions under Rule 23 (c)(4) alone. See F ED

. R. C IV

. P. 23(c)(2). Nor does Rule 23 (c)(4) contain any substantive criteria or requirements of its own for determining if class status is warranted or protecting the righ ts of absent class members

. It would be passing strange for a Rule as systematized , specific, and detailed as Rule 23 to unleash a distinct and wholly unregulated class device in (c)(4)’s single
sentence.

In short, Rule 23’s text and structure offer no quarter to the view that Rule 23(c)(4) creates an independent type of class action that is freed from all of Rule 23’s other class

- action prerequisites

. So t he district court should have ensured that the16

issue class it certified m et all, and not just some, of Rule 2 3 (a) and (b)’s preconditions to class status.

B

1

Applying Rule 23(a) to the issue clas s before us, we agree with the district court that th ose class

- action prerequisites are satisfied.

First, the proposed class meets Rule 23(a)(1)’s numerosity requirement. See Harris III , 2020 WL 5702085, at *4

– 5. “The numerosity requirement requires examination of the specific facts of each case and imposes no absolute limitations.” General Tel. Co. of the Nw. v. Equal Emp. Opportunity Comm ’ n , 446 U.S. 318, 330 (1980).

In this case, t here are 862 putative issue class members. See Harris III , 2020 WL 5702085, at *5. MTM “does not dispute these numbers and makes no arguments against numerosity[.]” Id. We agree with the district court that such a class qualifies as “so numerous that joinder of all members is impracticable[.]” See F ED

. R. C IV

. P . 23(a)(1).

Second, the proposed class meets Rule 23(a)(2)’s commonality requirement. “Commonality requires the plaintiff to demonstrate that the class members ‘have suffered the same injury[.]’” Wal

- Mart Stores, Inc. v. Dukes , 564 U.S. 338, 349

– 350 (2011) (quoting General Tel

. Co

. of Sw. v. Fa lcon

, 457 U.S. 147, 157 (1982)). That means that putative17
class members’ “claims must depend upon a common contention[.]” Id. at 350.

In this case, there a re “at least two” questions of law or fact common to the class: “(1) Whether MTM qualifies as a ‘join t employer’ and (2) whether MTM qualifies as a general contractor” under D.C. law. Harris III , 2020 WL 5702085, at *5. Those common conten tions and proposed common ans wer cut across all putative class members and depend on common evidence , satisfying the commonality requirement

. MTM argues that the commonality requirement is not met becau se there is no “common policy or course of conduct” by MTM across the class. MTM Opening Br. 34 (citing Dukes

, 564 U.S. at 344

– 345). But Rule 23(a)(2) does not require that

a single policy or course of conduct be the throughline for all plaintiffs. Rather, the putative class members must have a “common contention” of “ such a nature that it is capable of classwide resolution

— which means that determinatio n of its truth or falsity will resolve an issue that is central to the validity of each one of the claims in one stroke.” Dukes

, 564 U.S. at 350. T he questions of whether MTM is a joint employer to the Drivers or a general contractor under D.C. law are t wo such questions

. That is, d etermining whether MTM crosses the threshold of liability is “central to ” and potentially dispositive of “ the validity” of the Drivers’ claims

, see id.

Finally

, t he district court found, and MTM does not dispute, that the Dri vers’ claims and defenses are typical of the class and that they and their counsel will fairly and adequately represent the class. See F ED

. R. C IV

. P. 23(a)(3

– 4) ; Harris III
, 2020 WL 5702085, at *6

– 7. We agree

. On this record, no distinction between th e Drivers’ claims and defenses and those of the other class members has been identified

. See J.D. v. Azar , 925 F.3d 1291, 1322 (D.C. Cir. 2019) (per curiam) (“[T]o18
destroy typicality, a distinction must differentiate the ‘claims

or defenses’ of the representatives from those of the class.”) (emphasis omitted). Nor is there any conflict of interest between them and the class. See Amchem Prod s ., Inc. , 521 U.S. at 625 (“ T he adequacy inquiry under Rule 23(a)(4) serves to uncover confli cts of interest between named parties and the class they seek to represent. ”)

.

2

a

Where the district court erred was in failing to ensure that the issue class also satisfied one of the three types of authorized class actions under Rule 23 (b )

. The parties agree that the only relevant class type in this case is a (b)(3) class

. T he Drivers originally sought certification under Rule 23(b)(3)

, and the district court examined only the relationship between Rule 23(b)(3) and Rule 23(c)(4) before certi fying the issue class

. The problem , though, is that the district court failed to find that within the issues for the certified class

— whether MTM is a joint employer or general contractor

— common questions of law or fact predominate over individual ques tions , as Rule 23 (b)(3) requires

. See F ED

. R. C IV

. P. 23(b)(3)

. The court also failed to find that the use of an issue class to address those questions would be a superior litigation device to other available tools for resolving the common questions. See id

. Without those predicate determinations , the district court erred in certifying an issue class under Rule 23(c)(4)

. In addition, because th e issue class arise s under Rule 23(b)(3), the district court had to determine how notice could e ffectively be given in the case. See F ED

. R. C IV

. P. 23(c)( 2) (B) . Notice is an indispensable component of a class action under Rule 23(b)(3)

.19

Yet the court did not address how notice would be administrable for this class

.

The Drivers argue that the dis trict court did make th e required (b)(3) findings when it ruled on the initial motion for class certification, see Harris III , 2020 WL 5702085, at *7 , and that it silently incorporated th ose findings into its certification of the issue class

. S ee Harris Br. 6 ; Oral Arg. Tr. 48

.

The Drivers are mistaken. T he district court said that it would consider predominance only “ after identifying issues suitable for class treatment[,]” and then it only reviewed predominance as to the two issues for which it did not certify an issue class. See Harris IV , 2021 WL 3472381
, at *8, *10

– 11 ; see also Oral Arg. Tr. 48

– 50 ( Drivers’ counsel unable to point the court to predominance analysis for the certif ied issues ); see also Harris Br. 6 (describing the district court as relying on Harris III analysis “except as to predominance”). Nor did the district cour t ever fin d

— in the original class

certification decision or otherwise

— that the issue class met th e superiority requirement

. Because the analysis underlying the class certification judgment omitted those key determinations, we remand for the district court to determine whether its issue class can appropriately be maintained under all of the Rule 23( b)(3) criteria and consistent with Rule 23(c)(2) (B) ’s notice mandate. We outline next s ome of the key elements of those inquiries implicated in this case

.

b

In undertaking the predominance inquiry on remand, the district court must ensure that the commo n questions within the certified issues predominate over any individual ones. T he20

district court must also evaluate the relationship any certified issues have as to the dispute as a whole . A certified issue class should encompass a reasonably and workabl y segregable aspect of the litigatio n . For example, an issue class may be appropriate where common questions predominate as to (i) the determination of liability , giving rise to a liability

- only issue class ; (ii) proof of a key element of a cause o f action , such that there is an issue class for that element ; or (iii) a nother aspect of the controversy that, if decided , would material ly advance the fair resolution of the litigation.

We start with common ground , which is that Rule 23(c)(4) may be used to certify an issue that is less than an entire cause of action. See Harris Br. 9; Oral Arg. Tr. 11, 15, 19 ; see also F ED

. R. C IV

. P. 23(c)(1)(B) (district court’s order certifying class action “must define the class and the class * * * issues”).

One common use of Rule 23(c)(4) is for resolving the issue of liability

. See In re Brewer
, 863 F.3d at 875

– 876 (noting that district courts have the discretion to “certif[y] a Rule 23(c)(4) issue class on liability alone”). Even wher e d amages for a putative class action may require individualized calculations

, courts have routinely held t hat th ose individual considerations do not necessarily preclude certification of a class

— a s long as the liability issue is common to the class and that commonality predominates over any other individualized components of the li tigation

. See Tyson Foods , 577 U.S. at 453

– 454 (Where “one or more of the central issues in the action are common to the class and can be said to predominate, the action may be considered proper under Rule 23(b)(3) even though other important matters will have to be tried separately, such as damages or some affirmative defenses peculiar to some individual class members.”) (citatio n omitted); McCarthy v. Kleindienst , 741 F.2d 1406, 1415 (D.C. Cir. 1984) (“A district court should, of course, ordinarily consider such well

-21
established methods as bifurcating the trial into liability and damages phases before denying certification.”) ; id

. ( “ [T] he mere fact that damage awards will ultimately require individualized fact determinations is insufficient by itself to preclude class certification

. ”)

. Similarly, courts have embraced the use of a Rule 23(c)(4) issue class for liability only , ev en if the remedial claims destroy predominance for the cause of action as a whole. See, e.g.
, Nassau County , 461 F.3d at 227 (“[A] court may employ subsection (c)(4) to certify a class as to liability regardless of whether the claim as a whole satisfies R ule 23(b)(3)’s predominance requirement.”); Pella Corp. v. Saltzman , 606 F.3d 391, 394 (7th Cir. 2010) (per curiam) (“A district court has the discretion to split a case * * * by certifying a class for liability alone where damages * * * may require individualized assessments.”)

. 2

A s MTM pointed out at oral argument, certification of an issue class can also be appropriate where there is an affirmative defense applicable to a large number but not all class members. See Oral Arg. Tr. 6, 11, 15; c f

. Nassau County , 461 F.3d at 230 (holding that district court erred by finding that presence of affirmative defense barred certification of liability class); see

2 See also, e.g.

, F ED

. R. C IV

. P. 23 A dvisory C omm ittee’s N ote to 1966 amendment, 39 F.R.D. 69, 106 (1966) (Under Rule 23(c)(4), “in a fraud or similar case the action may retain its ‘class’ character only through the adjudication of liability to the class; the members of the class may thereafter be required to c ome in individually and prove the amounts of their respective claims.”); cf. Smilow v. Southwestern Bell Mobile Sys., Inc. , 323 F.3d 32, 41 (1st Cir. 2003) (“[E]ven if individualized determinations were necessary to calculate damages, Rule (23)(c)(4)(A) wo uld still allow the court to maintain the class action with respect to other issues.”) (referring to the pre

2007 version of Rule 23(c)(4))

.22

also Smilow v. Southwestern Bell Mobile Sys., Inc. , 323 F.3d 32, 39 (1st Cir. 2003) (discussin g the role of affirmative defenses in Rule 23(b)(3) predominance analysis).

Courts have also recognized other appropriate issues for (c)(4) issue classes. See
, e.g. , Russell , 15 F.4th at 270 (holding that “district courts may certify ‘particular issues’ for class treatment even if those issues, once resolved, do not resolve a defendant’s liability ” ) (quoting F ED

. R. C IV

. P . 23(c)(4)); McReynolds , 672 F.3d at 490

– 491 ( finding that disparate impact claims could “most efficiently be deter mined on a class

wide basis, consistent with” Rule 23(c)(4)); Valentino , 97 F.3d at 1 2 34 (“Rule 23 authorizes the district court in appropriate cases to isolate the common issues under [Rule 23(c)(4)] and proceed with class treatment of these particular is sues.”). Only

one c ircuit has suggested otherwise. See Castano , 84 F.3d at 745 n.21 ( observing in dicta that “ a cause of action, as a whole, must satisfy the predominance requirement of (b)(3 ) ”)

.

But when creating issue classes, district courts must hee d Rule 23 ’s carefully calibrated limits on class certification. The predominance inquir y “tests whether proposed classes are sufficiently cohesive to warrant” class litigation of their substantive claims

, rather than bring ing individual suit s

. See Amchem Prods., Inc. , 521 U.S. at 623. In that way, the predominance inquiry is an important safeguard against unreasonably fractured litigation , and simultaneously protects the rights of named parties and absent class members alike

. See id. at 615 (P redominance ensures that the class action is “promot[ing] * * * uniformity of decision as to persons similarly situated, without sacrificing procedural fairness or bringing about other undesirable results.” ) (internal quotation marks omitted). Predominanc e also helps courts establish that evidence can be fairly and sensibly presented in a way that protects the parties’ competing interests. See Russell , 15 F.4 th23
at 270; 2 N EWBERG & R UBENSTEIN § 4:49 (The predominance requirement ensures that individual cla ss members are “sufficiently similarly situated” such that “due process permits their claims to be compromised in the aggregate.”).

So district courts must ensure that Rule 23(c)(4)’s authorization of issue classes does not end up at war with Rule 23(b )(3)’s predominance requirement: Plaintiffs cannot effectively skirt the functional demands of the predominance requirement by seeking certification of a n overly narrow issue class and then arguing that the issue (inevitably) predominates as to itself. Cf. Castano , 84 F.3d at 745 n.21 (noting that such an interpretation would “eviscerate the predominance requirement”).

Nor can predominance become a tautological inquiry. Instead, when certifying an y issue class, the district court must explain how , within the context of the particular litigation before it, common questions predominate within a reasonably and workabl y segregable component of the litigation

. An issue class cannot consist of a single common question that predominates as to itself. Lastly, b ecause the baseline for predominance is the resolution of all issues within a fair and administrable trial process , courts must also address how dividing the litigation through the creation of an issue class protects all parties’ interests in the full presentation of their claims and evidence

.

c

In applying the superiority requirement on remand, the district court must explain how the use of issue classes is “superior to other available methods for fairly and efficiently adjudicating the controversy.” F ED

. R. C IV

. P. 23(b)(3)

. This requirement “ reinforce[s] the point that the court with the aid24
of the parties ought to assess the relative advantages of alternative pro cedures for handling the total controversy[.] ” F ED

. R. C IV

. P. 23 Advisory Committee’s Note to 1966 amendment, 39 F.R.D. 69, 103 (1966)

. The superiority requirement ensur es that class adjudication make s the litigation more manageable and promotes the prompt and efficient resolution of the case. See,
e.g. , Ortiz v. Fibreboard Corp. , 527 U.S. 815, 860 (1999) (“One great advantage of class action treatment of mass tort cases [at issue in Ortiz ] is the opportunity to save the enormous
transa ction costs of piecemeal litiga tion [

. ] ”); Califano

, 442 U.S. at 701 (“[T]he class

- action device saves the resources of both the courts and the parties by permitting an issue potentially affecting [the putative class members] to be litigated in an economica l fashion under Rule 23.”).

T he district court here did not explain how creating th is issue class w as superior to other potential ways of handling the litigation. Neither was the Drivers’ counsel at oral argument able to identify any benefits to judici al economy that would make class litigation superior to other trial management tools in this case , beyond tolling the statute of limitations

. See Oral Arg. Tr. 41

– 43.

Yet one alternative to class litigation might be deciding a partial summary judgment motion focused on the issues proposed to be certif i ed

— such as MTM’s employer or general
contractor status

. See Wright v. Schock , 742 F.2d 541, 543

– 544 (9th Cir. 1984) (“Under the proper circumstances

— where it is more practicable to do so and wher e the parties will not suffer significant prejudice

— the district court has discretion to25
rule on a motion for summary judgment before it decides the certification issue.”).

To be sure, Rule 23(c)(1)(A) directs the district court to determine the question of certification “[a]t an early practicable time [

. ] ” F ED

. R. C IV

. P. 23(c)( 1 )(A)

. And our district court’s Local Rules require a certification motion within 90 days of filing the complaint, absent an extension by the district court. See Local R ule 23.1(b).

But the district court in this case suspended the 90

- day deadline pending the resolution of MTM’s motion to dismiss. See Minute Order, Harris
, No. 17 Civ. 01371 (D.D.C. Oct. 26, 2017). And the litigation here unfolded a t such a pace that the motion to certify the class was not fully submitted until the case was nearly three years old. The district court therefore should at least have considered whether, at that point, it remained a superior form of litigation to certify an issue class rather than
to resolve the threshold question s going to MTM’s potential liability by way of a partial summary judgment motion ( such

as the Drivers’ pending summary judgment motion on MTM ’s
status as a joint employer or a general contractor ).

d

Finally, the district court’s indication that notice is not required for an issue class under Rule 23(b)(3) was incorrect

. In acting on MTM ’s renewed motion for a stay pending appeal, the court dismissed MTM’s argument that it would be irreparably harmed by the issuance of class notice that might have to be withdrawn later. The court explained that there would be no irreparable harm to MTM, agreeing with the Drivers that no notice needed to be issued for the (c)(4) cla ss

. See Harris v. Med ical Transp

. Mgmt., Inc. , No. 17 Civ. 01371
, 2022 WL 1908822, at *2 (D.D.C. June 3, 2022) (citing Pls.26
Mem. Opp. Mot. Stay Pending Appeal at 6

– 7, No. 17 Civ. 01371 (D.D.C. April 8, 2022), Dkt. 213)

. 3

That cannot be correct. Beca use th i s issue class should have been handled as a Rule 23(b)(3) class type , all of the procedural protections of such a class apply

. That includes notice of class certification. Compare F ED

. R. C IV

. P

. 23(c)(2)(A) (“For any class certified under Rule 23(b)(1) or (b)(2), the court may direct appropriate notice to the class.”)

, with F ED

. R. C IV

. P . 23(c)(2)(B) (“For any class certified under Rule 23(b)(3) * * * the court must direct to class members the best notice that is practicable under the circumstances[.]”) (emphases added)

. Rule 23(b)(3)’s notice mandate means what it says

, a nd for good reason. Because t he resolution of the action will bind absent class members , basic principles of due process require that they be notified that their individual claims are being resolved, and that they may opt out of the action if they so choose

. See Dukes , 564 U.S. at 363; Phillips Petrol

. Co. v

. Shutts , 472 U.S. 797
, 812 (1985)

.

So i f the district co urt certifies the issue class under Rule 23(b)(3) on remand , it must direct “the best notice that is practicable” as part of any certification ord er. See F ED

. R. C IV

. P . 23( c)(2)(B).

3 Following oral argument in this court, the Drivers asked the district court to direct notice to the class, a req uest that MTM opposed. See Pls. Mot. Amend the Cert. Order & Direct Notice to the Class, Harris , No. 17 Civ. 01371 (D.D.C. Nov. 10, 2022), Dkt. 228 ; Mem. Opp. to Pls. Mot. to Amend/Correct Cert. Order & Direct Notice to the Class, Harris , No. 17 Civ. 0137 1 (D.D.C. Nov. 23, 2022), Dkt. 229. That motion remains pending.27

V

MTM separately urges th is court to exercise pendent appellate jurisdiction and reverse the district court’s denial of its motion to decertify the FLSA collective. We decline to review that portion of the district court’s decision.

A

The FLSA sets out certain wage

- and

- hour protections for eligible employees

. For example, covered employers must pay a minimum hourly wage and provide overtime pay to employees for hours worked beyond 40 hours a week. 29 U.S.C. § § 2 06, 207. The FLSA also authorizes aggrieved
emp loyees to file suit to enforce their rights under the statute. See id. § 216.

As relevant here, the FLSA authorizes “collective action” litigation

. A n FLSA collective action may be maintained “by any one or more employees for and in behalf of himself or themselves and other employees similarly situated.” 29 U.S.C. § 216(b). To be bound by the judgment or to recover in an FLSA collective action, an employee must affirmatively opt into the litigation by filing written consent with the district
court. See id. ; Lindsay v. Government Emps. Ins. Co. , 448 F.3d 416, 419 (D.C. Cir. 2006).

Separate from its class action ruling, t he district court ruled that the Drivers’ collective action to enforce the wage provisions of the FLSA was proper and could go forward

, denying MTM’s motion to decertify the FLSA class

.28

B

This court has jurisdiction to review “final decisions” of the district court s , 28 U.S.C. § 1291, a s well as certain types of interlocutory orders

, s ee , e.g. , id. §§ 158(d)(2)(A); 1292 ; 1 8 U.S.C. § 3731 ; F ED

. R. C IV

. P. 23(f)

. The district court’s denial of MTM’s motion to decertify the FLSA collective is a nonfinal order that is not within our ordinary jurisdiction because it does not terminate the action on the merits. See Gelboim v. Bank of Am erica Corp. , 574 U.S. 405, 408

– 4 09 (2015) (“A ‘final decision’ is one ‘by which a district court disassociates itself from a case.’”) (quoting Swint v. Chambers County Comm’n , 514 U.S. 35, 42 (1995) ); Catlin v. United States , 324 U.S. 229, 233 (1945) ( A final decision “ends the litigatio n on the merits and leaves nothing for the court to do but execute the judgment

. ”). Nor does any law authorize the interlocutory review of collective action determinations under the FLSA.

So t o review the district court’s denial of MTM’s motion to decer tify the FLSA collective, we would have to exercise pendent appellate jurisdiction over the FLSA dispu te as part of our review under Rule 23(f) of the separate ly certified issue class

. Pendent appellate jurisdiction operates “when, in the course of reviewing an order from which an appeal is within its jurisdiction, ” an appellate court also reviews “ another order that, while part of the same case or controversy, would not otherwise be within its statutory jurisdiction.” Gilda Marx, Inc. v. Wildwood E xercise, Inc. , 85 F.3d 675, 678 (D.C. Cir. 199 6 )

. Because interlocutory appeals are generally disfavored and neither a statute nor rule specifically authorizes the use of pendent jurisdiction

, we exercise such jurisdiction “sparingly”29

and only “when subst antial considerations of fairness or efficiency demand it.” See id. at 678

– 679 ; id. at 680 (finding “no occasion to take the disfavored step of exercising pendent jurisdiction” “[w]ithout a reason to believe that the interests of judicial economy and fairness to the parties would be served”) (internal quotation marks and citation omitted).

Pendent jurisdiction might be warranted, though , “when the nonappea l a b le order is ‘inextricably intertwined’ with the appealable order, or when review of the former is ‘necessary to ensure meaningful review of the latter.’” Gilda Marx , 85 F.3d at 679 (quoting Swint , 514 U.S. at 51)

. Yet e ven if that standard is met, the ulti mate decision whether to grant pendent appellate jurisdiction lies within the court’s discretion. S ee Kilburn v. Socialist People ’ s Libyan Arab Jamahiriya , 376 F.3d 1123, 1136 (D.C. Cir. 2004) (“In the final balance, whether or not we have authority to ex ercise pendent appellate jurisdiction in this case, there is no question that we have discretion to decline to do so. ”).

On this record, an exercise of pendent appellate jurisdiction is not warranted for three reasons.

First , because collective actions differ materially from Rule 23 class actions and because they each enforc e different substantive claims, our review of the district court’s collective action ruling would stand dis tinct from

— not be intertwined with

— our Rule 23( f) review of the class action certification order. Which means that a ppellate r eview of the former is not at all necessary to our review of the latter

. Rule 23 actions , in fact, “ are fundamentally different from collective actions under the FLSA[.]” Gen esis Healthcare Corp. v. Symczyk , 569 U.S. 66, 74 (2013)

. O ur analysis of Rule 23 ’s application to the issue class certified by the district court has little relevant overlap with the decision whether or not to allow the FLSA30

collective action , which is not an issue

- specific action and turns on a distinct legal analysis

. The collective action covers all identified FLSA issues as a group, not issue by issue

.
In addition, the two group litigation mechanisms diverge in terms of their substantive requireme nts. While Rule 23 mandates several prerequisites for class certification and management of the litigation

— including, for example, Rule 23(b)(3)’s predominance and superiority requirements

— the FLSA only provides that party plaintiffs must be “similarly si tuated” to certify a collective. Those are quite different questions, requiring different textual and precedential analyses. See Myers v. Hertz Corp. , 624 F.3d 537, 555

– 556 (2d Cir. 2010) (declining to exercise pendent appellate jurisdiction over FLSA de cision because it was not inextricably intertwined with Rule 23; rather, Section 216(b)’s “similarly situated” inquiry is “quite distinct from the question whether plaintiffs have satisfied the much higher threshold” of Rule 23(b)(3) predominance).

N or does the collective action implicate the due process concerns underlying the Rule 23(b)(3) issue classes and their notice requirements. While Rule 23(b)(3) presumes that absent class members are represented in the litigation , unless they opt out, FLSA actions only include individuals who affirmatively opt into the litigation. Compare F ED

. R. C IV

. P. 23(c)(2)(B) and F ED

. R. C IV

. P. 23(e)(4)

, with 29 U.S.C. § 216(b) ; see also Lindsay , 448 F.3d at 419 (“ Unlike the procedure set out in 29 U.S.C. § 216(b), Rule 23 [(b)(3)] class certification requires notice to all potential class members that they must affirmatively decline to join ( ‘ opt out [of] ’ ) the lawsuit if they do not want to be class members. ”)

.

These “significant differences between certification under [Rule] 23 and the joinder process under [Section] 216(b) [,] ”31
Genesis Healthcare Corp. , 5 6 9 U.S. at 71 n.1
, illustrate how review of the colle ctive action certification and the Rule 23 class certificatio n share little common ground and, instead, “ are fundamentally different creatures

. ” Reinig v. RBS Citizens, N.A. , 912 F.3d 115, 131 (3d Cir. 2018)

. MTM argues that pendent appellate jurisdiction is warranted because the district court described the que stion of whether to certify an issue class in the same terms as the question of whether to decertify the FLSA collective

— namely, as hinging on whether it would “materially advance the litigation[.]” See Harris IV , 2021 WL 3472381, at *9 (quoting McLaughli n , 522 F.3d at 234).

That is not sufficient. This court is not bound by the district court’s characterization of the questions before it. Rather, “it is the ‘issues presented’ to this Court that must be ‘inextricably intertwined’ for pendent appellate jurisdiction to be properly exercised, not the issues presented to the district court.” Myers , 624 F.3d at 55 6 (quoting CFTC v. Walsh , 618 F.3d 218, 225 n.3 (2d Cir. 2010)) . The class action analysis undertaken on this appeal has no relevant overlap with the collective action objections that MTM raises.

Second , several considerations affirmatively weigh against the exercise of pendent appellate jurisdiction. See generally Gilda Marx
, 85 F.3d at 679. To begin, t he FLSA appeal concerns a different cause of action altogether from the Rule 23(f) petition

. See id. at 678. What is more, the FLSA appeal would require us to set out a standard for “similarly situated,” which thi s circuit has not yet done, and which would require32
wading into a circuit conflict. 4 Given that, granting pendent appellate review would add weighty and entirely distinct issues to our interlocutory revie w

— issues that have no overlap with the Rule 23 question of issue

- class certification

.

Review of the FLSA order would also be interlocutory

, which further weighs against exercising pendent appellate jurisdiction. See Gilda Marx

, 85 F.3d at 679. Granting r eview would compound the departure from or dinary principles of finality

. See id. And because the issues to review have no overlap with the Rule 23 inquiry, the disruption to district court proceedings would be doubled. Plus, were we to review the FLSA question, we would be “reaching an issue th at might be

4 Compare, e.g. , Scott , 954 F.3d at 516 (“[T]o be ‘similarly situated’ means that named plaintiffs and opt

- in plaintiffs are alike with regard to some material aspect of their litigation .”)

, and Campbell , 903 F.3d at 1114 (“[P]arty plaintiffs must be alike with regard to some material aspect of their litigation.”)

, with Thiessen v. Gen eral Elec. Cap. Corp. , 267 F.3d 1095, 1103 (10 th Cir. 2001) (weighing “several factors, including (1) disparate factual and employment settings of the individual plaintiffs; (2) the various defenses available to defendant which appear to be individual to each plaintiff; [and] (3) fairness and procedural considerations”) (internal quotation marks omitted); Anderson v. Cagle ’ s, Inc. , 488 F.3d 945, 953 (11th Cir. 2007) (“[ T] he similarities necessary to maintain a collective action under § 216(b) must extend beyond the mere facts of job duties and pay provis ions.”) (internal quotation marks and citation omitted); Morgan v. Fam ily Dollar Stores, Inc. , 551 F.3d 1233, 1262 (11th Cir. 2008) (“[T]he district court must consider whether the defenses that apply to the opt

- in plaintiffs’ claims are similar to one ano ther or whether they vary significantly.”) (citing Anderson , 488 F.3d at 954 n.8); and Halle v. W est Penn Allegheny Health Sys. Inc. , 842 F.3d 215, 226 (3d Cir. 2016) (“ Our Court * * * consider [s] all relevant factors and mak [es] a determination on a case

- by

- case basis as to whether the named plaintiffs have satisfied this burden by a preponderance of the evidence. ”).33
mooted or altered by subsequent district court proceedings.” See id.

Third

, the district court de clined to certify the collective action question for interlocutory review under 28 U.S.C. § 1292(b)

. Harris V , 2021 WL 5446829, at *4. The cour t explained that MTM had failed to demonstrate “that interlocutory appeal will materially advance the disposition of the litigation.” Id

. While the district court’s Section 1292(b) judgment does not control our pendent jurisdiction decision, the district cour t’s expert judgment on trial management is a relevant con sideration weighing against an exceptional exercise of pendent jurisdiction. See Swint , 514 U.S. at 47 (“Congress * * * chose to confer on district courts first line discretion to allow interlocutory appeals.”)

. For those reasons, pendent appellate jurisdiction would not be appropriate in this case.

V I

Because the district court failed to determine whether the classes it certified met Rule 23(a ) and (b)’s prerequisites, we remand the order certifying an issue class under Federal Rule of Civil Procedure 23(c)(4) for further consideration consistent with this opinion. We decline t o exercise pendent appellate jurisdiction over the district court’s denial of decertification of the FLSA collective.

So ordered.