FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

TROY LAMBERT, on Behalf of

Themselves and All Others Similarly

Situated,

Plaintiff-Appellant,

v.

NUTRACEUTICAL CORP.,

Defendant-Appellee.

No. 15-56423

D.C. No.

2:13-cv-05942-

AB-E

OPINION

Appeal from the United States District Court

for the Central District of California

André Birotte, Jr., District Judge, Presiding

Argued and Submitted March 9, 2017

Pasadena, California

Filed September 15, 2017

Before: Richard A. Paez, Marsha S. Berzon,

and Morgan Christen, Circuit Judges.

Opinion by Judge Paez
2 LAMBERT V. NUTRACEUTICAL CORP.

SUMMARY*

Fed. R. Civ. P. 23(f) & 23(b)(3) / Class Certification

The panel concluded that plaintiff’s Fed. R. Civ. P. 23(f)

petition for class certification was timely filed with this court;

reversed the district court’s order decertifying the class; and

remanded for further proceedings.

Rule 23(f) governs interlocutory appeals of “order[s]

granting or denying class-action certification,” and requires

that a petition for permission to appeal be filed “within 14

days after the order is entered.” Fed. R. Civ. P. 23(f). The

plaintiff filed his motion for reconsideration twenty days after

the district court decertified the class.

The panel held that the fourteen-day Rule 23(f) deadline

was not jurisdictional. Specifically, the panel that under

Bowles v. Russell, 551 U.S. 205 (2007), and Eberhart v.

United States, 546 U.S. 12 (2005), the Rule 23(f) deadline

was not jurisdictional because it was procedural, did not

remove a court’s authority over subject matters or persons,

and was in the Federal Rules of Civil Procedure, rather than

in a statute.

The panel held that because the Rule 23(f) deadline was

not jurisdictional, equitable exceptions, such as tolling, might

apply. The panel also held that a motion for reconsideration

filed within the Rule 23(f) deadline would toll the deadline. 

* This summary constitutes no part of the opinion of the court. It has

been prepared by court staff for the convenience of the reader.
LAMBERT V. NUTRACEUTICAL CORP. 3

The panel held that the Rule 23(f) deadline could be tolled

as a result of additional equitable circumstances. The panel

further held that a number of equitable factors supported

tolling the Rule 23(f) deadline. The panel held that because

plaintiff informed the court orally of his intention to seek

reconsideration of the decertification order and the basis for

his intended filing within fourteen days of the decertification

order and otherwise acted diligently, and because the district

court set the deadline for filing a motion for reconsideration

with which plaintiff complied, the Rule 23(f) deadline should

be tolled. The panel noted that other circuits would likely not

toll the Rule 23(f) deadline in this case, and would only allow

tolling when the motion for reconsideration was filed within

the fourteen-day period. The panel concluded that plaintiff’s

Rule 23(f) petition was timely filed in this court.

Turning to the merits of the certification petition, the

panel held that the district court abused its discretion in

decertifying the class on the basis of plaintiff’s inability to

prove restitution damages through the full refund model. 

Plaintiff brought his consumer class action under Fed. R. Civ.

P. 23(b)(3), which requires that a plaintiff show a class wide

method for damages calculations as a part of the assessment

of whether common questions predominate over individual

questions. The full refund model measures damages by

presuming a full refund for each customer, on the basis that

the product has no, or only a de minimis, value. The panel

held that because plaintiff’s damages model matched his

theory of liability, and because plaintiff had shown that his

damages model was supportable on evidence that could be

introduced at trial, the class should not have been decertified. 

The panel further held that whether plaintiff could prove

damages to a reasonable certainty on the basis of his full
4 LAMBERT V. NUTRACEUTICAL CORP.

refund model was a question of fact that should be decided at

trial on remand.

COUNSEL

Gregory Weston (argued) and David Elliott, The Weston

Firm, San Diego, California; Ronald A. Marron, The Law

Offices of Ronald A. Marron APLC, San Diego, California;

for Plaintiff-Appellant.

Steven N. Feldman (argued) and John C. Hueston, Hueston

Hennigan LLP, Los Angeles, California; Jon F. Monroy,

Monroy Averbuck & Gysler, West Lake Village, California;

for Defendant-Appellee.

OPINION

PAEZ, Circuit Judge:

Federal Rule of Civil Procedure 23(f) allows a litigant to

seek an interlocutory appeal of a district court’s order

granting or denying class certification. This case is about

whether and when the fourteen-day Rule 23(f) deadline may

be tolled. In a matter of first impression for this court, we

hold that the Rule 23(f) deadline is not jurisdictional, thus

equitable exceptions apply. We therefore hold that a motion

for reconsideration filed within the Rule 23(f) deadline will

toll the deadline. Parting ways with some of our sister

circuits, we further hold that additional equitable

circumstances may also warrant tolling. As a result, we hold

that the Rule 23(f) deadline was tolled here, when counsel for

the lead plaintiff, within fourteen days of the district court’s
LAMBERT V. NUTRACEUTICAL CORP. 5

decertification order, informed the court of his intention to

seek reconsideration, explained his reasons for doing so, and

the court set a date for filing the motion with which counsel

complied. As for the merits of the Rule 23(f) petition, we

hold that the district court abused its discretion in decertifying

the class, and therefore reverse and remand.

I.

Lambert purchased “Cobra Sexual Energy,” an alleged

aphrodisiac dietary supplement manufactured and marketed

by Nutraceutical, which the Food and Drug Administration

(“FDA”) had not approved. Labels on Cobra Sexual Energy

boasted that it contained performance-enhancing herbs that

would provide users with “animal magnetism” and “potency

wood.” On the basis of these labels, Lambert believed that

the product would enhance his sexual performance and

increase the frequency with which he could engage in sexual

activity. Had he known that the labels’ claims were false, he

would not have purchased the product.

According to Lambert, Cobra Sexual Energy violated the

FDA’s aphrodisiac drug rule because it claimed to increase

sexual desire but had not been through clinical testing, as

required by 21 C.F.R. § 310.528(c); nor had it received FDA

approval, as required by 21 C.F.R. § 310.528(b). The product

also failed to display prominently a disclaimer that it had not

been evaluated by the FDA, in alleged violation of 21 U.S.C.

§ 343(r)(6)(C). Moreover, Lambert alleges that the

supplement contained an ingredient, yohimbe, which is

dangerous for certain persons in certain doses, yet the product

label contained no warning of that risk.
6 LAMBERT V. NUTRACEUTICAL CORP.

Lambert brought a consumer class action for violations of

California’s Unfair Competition Law (“UCL”) (Cal. Bus. &

Prof. Code §17200 et seq.), False Advertising Law (“FAL”)

(Cal. Bus. & Prof. Code § 17500 et seq.), and Consumer

Legal Remedies Act (“CLRA”) (Cal. Civ. Code § 1750 et

seq.). Lambert brought his class action under Federal Rule of

Civil Procedure 23(b)(3), which provides that a class may be

certified if “questions of law or fact common to class

members predominate over any questions affecting only

individual members.”

The district court initially granted class certification on

the basis of the full refund damages model. That model

applies when a product is shown to be worthless, and

damages may be calculated by multiplying the average retail

price by the number of units sold. In granting class

certification, the district court concluded that Lambert put

forth a “tenable theory that monetary relief can be ascertained

on a classwide basis . . . [that] can be readily calculated using

Defendant’s sales numbers and an average retail price.” The

case was subsequently reassigned to a different district judge

because the original judge retired. Discovery proceeded and

closed. Nutraceutical then filed a motion for decertification

of the class, upon which the newly assigned district judge

held a hearing.

On February 20, 2015, the district court granted the

motion to decertify. The district court found that Lambert’s

full refund damages model was “consistent with his theories

of liability.” The court proceeded to find, however, that

Lambert “failed to provide the key evidence necessary to

apply his classwide model for damages,” so common issues

did not predominate. The district court required Lambert to
LAMBERT V. NUTRACEUTICAL CORP. 7

provide the actual average retail price, and Lambert had

provided only the suggested retail price.

During a March 2, 2015 status conference, ten days after

the order decertifying the class, Lambert informed the court

of his intention to file a motion for reconsideration. Counsel

explained that he had a damages model and evidentiary

support for it. The district court instructed Lambert to file the

motion for reconsideration within ten days—i.e., within

twenty days in total from the order decertifying the class.

As directed by the district court, ten days later, on March

12, 2015, Lambert moved for reconsideration and asked for

recertification. In his motion for reconsideration, Lambert

pointed to evidence he had presented in his class certification

motion showing that the suggested retail price could be used

in conjunction with other evidence to establish the full refund

damages model. Lambert also argued for the first time that,

as an alternative, he could prove damages through nonrestitutionary disgorgement.

The district court denied Lambert’s motion for

reconsideration three months later. The court rejected

Lambert’s contention that the average retail price could be

calculated from the suggested retail price. The district court

also rejected Lambert’s non-restitutionary disgorgement

argument, reasoning that he waived it by presenting it for the

first time in his motion for reconsideration. The court

proceeded to hold that even if Lambert had not waived the

non-restitutionary disgorgement argument, it was improper

under California law, as restitution should be measured by

what the plaintiffs lost, not by what the defendants gained; in

other words, the district court held, non-restitutionary
8 LAMBERT V. NUTRACEUTICAL CORP.

disgorgement is not available under California law.1In

addition to declining to recertify the class, the order set forth

a plan for notifying the class regarding decertification.

Within fourteen days of the order denying his motion for

reconsideration, Lambert filed in this court a Rule 23(f)

petition for permission to appeal the district court’s orders

granting the motion for class decertification and denying the

motion for reconsideration. Upon the filing of that petition,

the district court stayed proceedings pending appeal. A

motions panel of this court conditionally granted Lambert’s

Rule 23(f) petition, instructing the parties “[i]n addition to all

other issues the[y] wish to raise in their briefs in the appeal,

[to] . . . address the timeliness of this petition.”

II.

Because the motions panel only conditionally granted the

petition and referred the issue of timeliness to this panel, we

review de novo its timeliness. See Briggs v. Merck Sharp &

Dohme, 796 F.3d 1038, 1045–46 (9th Cir. 2015) (reviewing

the timeliness of a Rule 23(f) petition after the petition was

conditionally granted by a motions panel).

As to the merits of the petition, we review the district

court’s class decertification ruling for an abuse of discretion. 

Pulaski & Middleman, LLC v. Google, Inc., 802 F.3d 979,

984 (9th Cir. 2015); Yokoyama v. Midland Nat’l Life Ins. Co.,

1 While non-restitutionary damages refer to the defendant’s revenues

regardless of the plaintiff’s relationship to those damages, restitutionary

damages refer to the portion of the defendant’s revenues over which the

plaintiff has some ownership claim. See Korea Supply Co. v. Lockheed

Martin Corp., 63 P.3d 937, 941 (Cal. 2003).
LAMBERT V. NUTRACEUTICAL CORP. 9

594 F.3d 1087, 1090–91 (9th Cir. 2010). “A district court

would necessarily abuse its discretion if it based its ruling on

an erroneous view of the law or a clearly erroneous

assessment of the evidence.” United States v. Hinkson,

585 F.3d 1247, 1259 (9th Cir. 2009) (en banc) (quoting

Cooter & Gell v. Hartmax Corp., 496 U.S. 384, 405 (1990)). 

We review findings of fact in the class certification

determination for clear error. Abdullah v. U.S. Sec. Assocs.,

Inc., 731 F.3d 952, 956 (9th Cir. 2013).

III.

Rule 23(f) governs interlocutory appeals of “order[s]

granting or denying class-action certification.” Fed. R. Civ.

P. 23(f). The Rule requires that a petition for permission to

appeal be filed “within 14 days after the order is entered.” Id. 

Rule 23(f) is silent as to the effect of motions for

reconsideration on this deadline. Here, the district court

decertified the class on February 20, 2015. Lambert’s Rule

23(f) petition, however, was not filed until June 24, 2015,

fourteen days after the court denied his motion for

reconsideration. Under the plain text of Rule 23(f),

Lambert’s petition would be untimely because it was not filed

within fourteen days of the district court’s initial order

decertifying the class. In other words, unless an exception

applies, Lambert’s Rule 23(f) petition would be barred.

To determine whether Lambert’s Rule 23(f) petition is

timely, we must first determine whether Rule 23(f) is

jurisdictional. We conclude that it is non-jurisdictional, and

that equitable remedies softening the deadline are therefore

generally available. Specifically, we hold that a motion for

reconsideration filed within fourteen days of the certification

order tolls the Rule 23(f) deadline. We also hold that the
10 LAMBERT V. NUTRACEUTICAL CORP.

deadline can be tolled as a result of additional equitable

circumstances. In light of the circumstances in this case, we

conclude that the Rule 23(f) deadline was tolled and deem

Lambert’s petition timely.

A.

We turn first to whether the fourteen-daydeadline in Rule

23(f) is jurisdictional. Two Supreme Court cases primarily

guide our inquiry. In Eberhart v. United States, the Court

held that a deadline in the Federal Rules of Criminal

Procedure was not jurisdictional because it was a procedural

claim-processing rule, as opposed to a rule that delineated the

classes of cases or persons within a court’s adjudicatory

authority. 546 U.S. 12, 15–16 (2005). Several years later,

the Court held in Bowles v. Russell that deadlines contained

in statutes are jurisdictional, but non-statutorydeadlines, such

as those in the Federal Rules of Civil or Criminal Procedure,

may instead be procedural “claims-processing” rules. 

551 U.S. 205, 211–14 (2007).

We have not yet had occasion to apply these cases to Rule

23(f). We have, however, concluded that an immigration

regulation requiring a petitioner to file his notice of appeal

with the Board of Immigration Appeals within thirty days of

the immigration judge’s adverse ruling is not jurisdictional

because it is regulatory, rather than statutory. IrigoyenBriones v. Holder, 644 F.3d 943, 948–49 (9th Cir. 2011). In

Irigoyen-Briones, we also noted that the regulatory provision

that contained the deadline did not use the word

“jurisdiction,” and that the Supreme Court had narrowly

defined jurisdictional rules as those that remove a court’s

authority to hear a case. Id. 
LAMBERT V. NUTRACEUTICAL CORP. 11

The Third Circuit has had occasion to consider the

jurisdictional nature of Rule 23(f). In Gutierrez v. Johnson &

Johnson, the Third Circuit held that in light of Bowles, the

Rule 23(f) deadline is not jurisdictional because it is set forth

in a rule promulgated by the Supreme Court, not a statute

enacted by Congress. 523 F.3d 187, 197–98 (3d Cir. 2008). 

Other circuits have likewise suggested that the Rule 23(f)

deadline is not jurisdictional. See, e.g., Carpenter v. Boeing

Co., 456 F.3d 1183, 1190 n.1 (10th Cir. 2006) (noting that

although the court had previously held Rule 23(f) to be

jurisdictional, Eberhart “casts doubt” on that notion); Coco

v. Inc. Vill. of Belle Terre, N.Y., 448 F.3d 490, 491–92 (2d

Cir. 2006) (declining to decide whether Rule 23(f) is

jurisdictional, but noting that Eberhart “calls the

jurisdictional nature of Rule 23(f) into question”).

We conclude that under Bowles and Eberhart, the Rule

23(f) deadline is not jurisdictional because it is procedural,

does not remove a court’s authority over subject matters or

persons, and is in the Federal Rules of Civil Procedure, rather

than in a statute.

B.

Because the Rule 23(f) deadline is not jurisdictional,

equitable exceptions, such as tolling, may apply.

2 When

deadlines are not jurisdictional, courts may apply judicial

equitable exceptions to avoid or soften the time limitations. 

Bowles, 551 U.S. at 211–14; Gutierrez, 523 F.3d at 197 (“The

2 Equitable exceptions include tolling, the unique circumstances

doctrine, and others. See Gutierrez, 523 F.3d at 197. Because we resolve

this case on the basis of tolling, we need not address the unique

circumstances doctrine.
12 LAMBERT V. NUTRACEUTICAL CORP.

import of this distinction between jurisdictional and nonjurisdictional rules, according to the Supreme Court, is that

courts cannot create equitable exceptions to jurisdictional

time limits.”).

Equitable exceptions arise from the “traditional power of

the courts to apply the principles . . . of equity jurisprudence. 

The classic example is the doctrine of equitable tolling, which

permits a court to pause a statutory time limit when a litigant

has pursued his rights diligently but some extraordinary

circumstance prevents him from bringing a timely action.” 

Cal. Pub. Emps. Ret. Sys. v. ANZ Sec., Inc., 137 S. Ct. 2042,

2051 (2017) (citations and internal quotation marks omitted). 

“At bottom, the purpose of equitable tolling is to ‘soften the

harsh impact of technical rules which might otherwise

prevent a good faith litigant from having [her] day in court.’” 

Rudin v. Myles, 781 F.3d 1043, 1055 (9th Cir. 2015)

(alteration in original) (quoting United States v. Buckles,

647 F.3d 883, 891 (9th Cir. 2011)).

C.

All circuits to consider tolling the Rule 23(f) deadline

have held that the deadline may be tolled when a litigant files

a motion for reconsideration within the fourteen-day

deadline.3 These circuits have reasoned, for example, that

3

See Gutierrez, 523 F.3d at 193 (holding that “for the purpose of

tolling the time within which to file a Rule 23(f) petition, a ‘timely’

motion to reconsider is one that is filed within the [fourteen]-day period

set forth in Rule 23(f)”); Nucor Corp. v. Brown, 760 F.3d 341, 343 (4th

Cir. 2014) (stating that a motion for reconsideration filed within fourteen

days of the order granting or denying class certification can toll a Rule

23(f) deadline); Fleischman v. Albany Med. Ctr., 639 F.3d 28, 31–32 (2d

Cir. 2011) (same with respect to a motion to amend); In re DC Water &
LAMBERT V. NUTRACEUTICAL CORP. 13

“federal courts long have held that a motion for

reconsideration tolls the time for appeal, provided that the

motion is made within the time for appeal.” Blair v. Equifax

Check Servs., Inc., 181 F.3d 832, 837 (7th Cir. 1999). We

agree, and therefore hold, as a baseline matter, that a motion

for reconsideration filed within fourteen days of a

certification decision tolls the Rule 23(f) deadline.

D.

Of course, in this case, that holding does not end the

inquiry. Lambert did not file his motion for reconsideration

until twenty days after the district court decertified the class. 

We nonetheless hold that Lambert is entitled to tolling given

the history of this case.

Equitable exceptions such as tolling are meant to allow a

“a good faith litigant” to have “[her] day in court.” Rudin,

781 F.3d at 1055 (alteration in original) (internal quotation

marks omitted). Accordingly, in determining when equitable

circumstances beyond a motion for reconsideration filed

within the fourteen day Rule 23(f) deadline can toll that

deadline, we look to equitable factors such as whether the

litigant “pursued his rights diligently,” and whether external

circumstances, such as a deadline imposed by the district

Sewer Auth., 561 F.3d 494, 496 (D.C. Cir. 2009) (same with respect to a

motion for reconsideration); Jenkins v. BellSouth Corp., 491 F.3d 1288,

1291–92 (11thCir. 2007) (same); Carpenter, 456 F.3d at 1190–92 (same);

McNamara v. Felderhof, 410 F.3d 277, 281 (5th Cir. 2005) (same); Gary

v. Sheahan, 188 F.3d 891, 892 (7th Cir. 1999) (same); Shin v. Cobb Cty.

Bd. of Educ., 248 F.3d 1061, 1064 n.1 (11th Cir. 2001) (same); Blair v.

Equifax Check Servs., Inc., 181 F.3d 832, 836–37 (7th Cir. 1999) (same).
14 LAMBERT V. NUTRACEUTICAL CORP.

court,4affected the litigant. Cal. Pub. Emps. Ret. Sys., 137 S.

Ct. at 2050.

We also look, as a factor, to whether a litigant took some

other action similar to filing a motion for reconsideration

within the fourteen-day deadline, such as a letter or verbal

representation conveying an intent to seek reconsideration

and providing the basis for such action. We are not alone in

considering this as a factor. In McNamara v. Felderhof, the

Fifth Circuit considered whether tolling of Rule 23(f)’s

deadline was available when a litigant stated in a court filing

that he would seek reconsideration of certification within

fourteen days, but did not file a formal motion for

reconsideration within that time. 410 F.3d 277, 279–80 (5th

Cir. 2005). The Fifth Circuit concluded that a “Trial and

Case Management Plan” (“the Plan”) could toll the Rule 23(f)

filing deadline. Id. The Plan specifically sought “revisitation

and modification” of the class certification ruling. Id. at 280

(internal quotation marks omitted). The Fifth Circuit

reasoned that the Plan should be considered a motion for

4 Petitions for certiorari in the Supreme Court provide a useful

analogy. The advisory committee notes to Rule 23(f) provide that “[t]he

court of appeals is given unfettered discretion whether to permit the

appeal, akin to the discretion exercised by the Supreme Court in acting on

a petition for certiorari.” Fed. R. Civ. P. 23(f) advisory committee’s note

to 1998 amendment. In discussing the timeliness of a Rule 23(f) petition,

the Eleventh Circuit cited the advisory committee’s certiorari analogy. 

Jenkins, 491 F.3d at 1290; cf. Blair, 181 F.3d at 833–34 (looking to

petitions for certiorari to determine substantive standards for Rule 23(f)). 

Petitions for certiorari must be filed within ninety days, but may be filed

later when a timely petition for rehearing is granted or when the court of

appeals entertains an untimely petition for rehearing. Sup. Ct. R. 13(1),

(3). By analogy, much like the courts of appeals’ authority to affect the

Supreme Court’s certiorari petition deadline, district courts have authority

to affect the Rule 23(f) deadline.
LAMBERT V. NUTRACEUTICAL CORP. 15

reconsideration for tolling purposes because it “called into

question the correctness of the district court’s [certification]

order.” Id. The Fifth Circuit also reached this conclusion

because it “d[id] not read Rule 23(f) as so limiting in

nature.”5Id. The Seventh Circuit has stated, similarly, that

it does not “matter[] what caption the litigant places on the

motion to reconsider.” Gary v. Sheahan, 188 F.3d 891, 893

(7th Cir. 1999). Accordingly, an important factor in the

tolling analysis is whether the litigant provided, within the

Rule 23(f) deadline, notice of the intent to seek

reconsideration.

Here, a number of equitable factors support tolling the

Rule 23(f) deadline. Lambert clearly conveyed his intention

to file a motion for reconsideration seeking recertification on

the tenth day after entry of the order decertifying the class. 

At a status conference, Lambert specifically informed the

court of his intention to seek recertification and briefly

explained his reasons for doing so. The district court then

instructed Lambert to file his motion within ten days, which

allotted him twenty days in total from the decertification

order. The district court imposed the deadline after an

exchange with Lambert’s counsel as to whether it was

reasonable. Lambert complied, and filed his motion for

reconsideration within the period set by the district court. 

Lambert also filed the Rule 23(f) petition within fourteen

days after the district court denied the motion for

reconsideration. We hold that because Lambert informed the

court orally of his intention to seek reconsideration of the

decertification order and the basis for his intended filing

within fourteen days of the decertification order and

5 McNamara ultimatelydismissed the petition as untimely because the

Plan was not filed within the Rule 23(f) deadline.
16 LAMBERT V. NUTRACEUTICAL CORP.

otherwise acted diligently, and because the district court set

the deadline for filing a motion for reconsideration with

which Lambert complied, the Rule 23(f) deadline should be

tolled.

We recognize that other circuits would likely not toll the

Rule 23(f) deadline in Lambert’s case. To the extent other

circuits limit Rule 23(f) tolling only to the circumstance

where a motion for reconsideration is filed within fourteen

days of the certification order, we part ways with them. 

Other circuits have, for example, held that a motion for

reconsideration filed more than fourteen days after a

certification order will not toll the deadline even when the

district court set or influenced that deadline. In a case in

which a district court extended the time to file a motion for

reconsideration well beyond the Rule 23(f) deadline, the

Third Circuit held that even if a motion for reconsideration is

timely for the district court’s purposes, it is untimely if it is

filed outside of Rule 23(f)’s fourteen-day period. Gutierrez,

523 F.3d at 193 n.5 (“[A] motion to reconsider that is filed

more than [fourteen] days after an order granting or denying

class certification will not toll the time to file a 23(f) petition,

even if the motion is ‘timely’ as defined by the district court’s

rules or its scheduling order.”); see also Jenkins v. BellSouth

Corp., 491 F.3d 1288, 1289 (11th Cir. 2007) (providing that

a district court cannot manipulate the timeliness of a Rule

23(f) petition by vacating and reentering the order denying

class certification to make it timely); Delta Airlines v. Butler,

383 F.3d 1143, 1145 (10th Cir. 2004) (holding that even if a

district court extended the time to file a Rule 23(f) petition,

this could not toll the fourteen-day period because the district

court lacked such authority). Similarly, the Third Circuit held

that an informal letter to the district court conveying an intent

to seek reconsideration of a certification decision filed within
LAMBERT V. NUTRACEUTICAL CORP. 17

fourteen days would not toll the time to file a Rule 23(f)

petition, because it did not specifically request certification

nor provide reasons why the certification order was wrong. 

Gutierrez, 523 F.3d at 194–95.

The reasons offered by other circuits for strictly limiting

the availability of Rule 23(f) tolling, by only allowing for

tolling when a motion for reconsideration is filed within the

fourteen-day period, are not persuasive.

First, the fourteen-day deadline is for filing a Rule 23(f)

petition, not for filing a motion for reconsideration in federal

court. Thus, the fourteen-day limitation on tolling has no

basis in Rule 23 or any other Rule, but instead is a judicial

construct. Litigants have no reason to know that their

deadline for filing a motion for reconsideration is effectively

fourteen days, rather than whatever the district judge has

ordered.

Second, those circuits that have strictly construed the

Rule 23(f) fourteen-day deadline have reasoned that Rule

23(f) petitions slow down litigation, are disruptive, and inject

uncertainty into class action litigation.6 For example, the

6

In defining the substantive standards of Rule 23(f), we adopted

much of the reasoning discussed by other circuits with respect to timing:

First, the rule provides a mechanism through which

appellate courts, in the interests of fairness, can restore

equilibrium when a doubtful class certification ruling

would virtually compel a party to abandon a potentially

meritorious claim or defense before trial. And second,

the rule furnishes an avenue . . . [to] take earlier-thanusual cognizance of important, unsettled legal

questions, thus contributing to both the orderly progress
18 LAMBERT V. NUTRACEUTICAL CORP.

District of Columbia Circuit explained that “[c]ourts

generally disfavor interlocutory appeals because they disrupt

ongoing trial court proceedings and squander resources.” In

re DC Water & Sewer Auth., 561 F.3d 494, 497 (D.C. Cir.

2009); see also Shin v. Cobb Cty. Bd. of Educ., 248 F.3d

1061, 1064 (11th Cir. 2001) (describing Rule 23(f) petitions

as “an avenue of last resort” and “inherently disruptive, timeconsuming, and expensive”). The Third Circuit in Gutierrez

explained that, as a result, the Rule 23(f) deadline is

purposely short, to “ensure that interlocutory appeals of class

certification decisions are heard and decided in a timely

manner, so as not to disrupt the proceedings at the district

court level.” 523 F.3d at 199 (citing Fed. R. Civ. P. 23(f)

advisory committee’s note to 1998 amendment). The

Eleventh Circuit has expressed concern that appellate court

review generally takes more time than disposition by a trial

court. Shin, 248 F.3d at 1064. Moreover, the Seventh Circuit

explained that because class certification can have major

consequences for litigation strategies and resources, and for

the possibility of settlement, allowing for only one short

window of review “permit[s] the parties to proceed in

confidence about the scope and stakes of the case.” Sheahan,

188 F.3d at 893.

The premise that Rule 23(f) petitions are disruptive and

slow is not universally true and we decline to adopt any hard

and fast rule on the basis of such an idea. First, Rule 23(f)

of complex litigation and the orderly development of

law. . . . Interlocutory appeals are generally disfavored

because they are disruptive, time-consuming, and

expensive.

Chamberlan v. Ford Motor Co., 402 F.3d 952, 957–59 (9th Cir. 2005)

(per curiam) (citations and internal quotation marks omitted).
LAMBERT V. NUTRACEUTICAL CORP. 19

petitions do not actually slow down litigation. Rule 23(f)

petitions do not automatically stay district court

proceedings—only the district court can grant a stay, as it did

in this case, and it has discretion whether or not to do so. See

Blair, 181 F.3d at 835 (suggesting that such stays will be

infrequent). Likewise, district courts are bound to experience

delay when they are confronted with motions for

reconsideration, irrespective of any Rule 23(f) petition. The

district court in this case, for example, kept Lambert’s motion

for reconsideration under submission for more than three

months; and statistical studies by the Federal Judicial Center

show that median ranges for decisions on class certification

motions range from seven to fifteen months. See Thomas E.

Willging et al., Fed. Judicial Ctr., Empirical Study of Class

Actions in Four Federal District Courts: Final Report to the

Advisory Committee on Civil Rules 27 (1996),

http://www.uscourts.gov/sites/default/files/rule23_1.pdf. The

Third and Eleventh Circuits’ suggestions that district courts

“ordinarily” rule on motions for reconsideration more quickly

than appellate courts, and are “expect[ed]” to do so, are vague

and lack persuasive force in light of the evidence to the

contrary. See Gutierrez, 523 F.3d at 199; Shin, 248 F.3d at

1064. We recognize that Rule 23(f) petitions may lengthen

litigation. But so do motions for reconsideration of a class

action decertification decision when no 23(f) petition is filed,

which every circuit to consider the question has treated as

valid grounds for equitable tolling.

Third, Rule 23(f) petitions do not uniquely disrupt or

inject uncertainty into the litigation. Rule 23(c)(1)(C) allows

modifying or amending an order granting or denying class

certification up to the time of final judgment, at the discretion
20 LAMBERT V. NUTRACEUTICAL CORP.

of the district court. Fed. R. Civ. P. 23(c)(1)(C)7; see In re

DC Water &Sewer Auth., 561 F.3d at 497 (noting that district

courts may reconsider and modify class certification

throughout the case); Shin, 248 F.3d at 1064 (explaining that

district courts have the ability, “and perhaps even a duty,” to

reconsider certification as the case progresses). If the district

court may change its class certification decision at any time,

interlocutory review should not affect the parties’ level of

certainty as to the finality of that decision, nor should it be

unusually or particularly disruptive. See Michael G.

McLellan, If at First You Don’t Succeed: The Varying

Standards Applicable to Renewed Motions for Class

Certification, 30 A.B.A. ANTITRUST 89, 92 (Summer 2016)

(suggesting that Rule 23(f) and Rule 23(c)(1)(C) are strategic

alternatives available to class action litigants).

If anything, Rule 23(f) appellate review may increase the

level of certainty for litigants. Once an appellate court speaks

to class certification issues in a Rule 23(f) appeal, the district

court can no longer reconsider those issues under Rule

23(c)(1)(C), or at least its authority to do so will be narrowed

by the court of appeals’ ruling, thus enhancing certainty for

the parties and the district court. See McLellan, supra, at 92

(explaining that a Rule 23(f) decision constrains the district

court’s ability to alter or amend certification under Rule

23(c)(1)(C)) (citing Gene & Gene, L.L.C. v. BioPay, L.L.C.,

624 F.3d 698, 703 (5th Cir. 2010)).

In sum, we hold that (1) Rule 23(f)’s deadline is not

jurisdictional, (2) equitable exceptions therefore apply, such

7 Federal Rule ofCivil Procedure 23(c)(1)(C) provides: “An orderthat

grants or denies class certification may be altered or amended before final

judgment.”
LAMBERT V. NUTRACEUTICAL CORP. 21

that (3) motions for reconsideration filed within fourteen days

toll that deadline. We also hold that (4) equitable

circumstances beyond a formal motion to reconsider filed

within fourteen days can toll the Rule 23(f) deadline. As

discussed above, equitable circumstances tolled the Rule

23(f) fourteen-day deadline so that Lambert’s 23(f) petition

was timely filed in this court.8

IV.

As Lambert’s petition was timely, we turn to the merits,

and conclude that the district court abused its discretion in

decertifying the class on the basis of Lambert’s inability to

prove restitution damages through the full refund model.

Lambert brought his consumer class action under Federal

Rule of Civil Procedure 23(b)(3). “Under Rule 23(b)(3), the

court must find that ‘questions of law or fact common to class

members predominate over any questions affecting only

individual members.’” Pulaski, 802 F.3d at 985. A Rule

23(b)(3) plaintiff must show a class wide method for damages

8 The parties also debate whether an order granting a motion for

reconsideration provides a new fourteen-day window to file a Rule 23(f)

petition, because such an order is “an order granting or denying class

certification.” This would be another issue of first impression for this

court. Other circuits to consider the issue have held that petitioners

receive an additional fourteen days to file a Rule 23(f) petition if a motion

for reconsideration is granted and changes the status quo of class

certification, regardless of when the motion is filed. See Nucor Corp.,

760 F.3d at 343; Fleischman, 639 F.3d at 31; In re DC Water & Sewer

Auth., 561 F.3d at 496; Gutierrez, 523 F.3d at 194; Jenkins, 491 F.3d at

1291–92; Carpenter, 456 F.3d at 1191–92; McNamara, 410 F.3d at 281. 

We need not decide this question, as we hold that Lambert’s petition was

timely under a tolling theory, and, in any case, the district court denied

Lambert’s motion.
22 LAMBERT V. NUTRACEUTICAL CORP.

calculations as a part of the assessment of whether common

questions predominate over individual questions. Leyva v.

Medline Indus. Inc., 716 F.3d 510, 514 (9th Cir. 2013). The

party seeking to maintain class certification bears the burden

of demonstrating that the Rule 23 requirements are satisfied,

even on a motion to decertify. Marlo v. United Parcel Serv.,

Inc., 639 F.3d 942, 947 (9th Cir. 2011); United Steel Workers

v. ConocoPhillips Co., 593 F.3d 802, 807 (9th Cir. 2010).

We have repeatedly emphasized that uncertain damages

calculations should not defeat certification. In Yokoyama, we

held that “damage calculations alone cannot defeat

certification.” 594 F.3d at 1094. After our decision in

Yokoyama, the Supreme Court held in Comcast that a Rule

23(b)(3) plaintiff must show that “damages are capable of

measurement on a classwide basis.” Comcast Corp. v.

Behrend, 133 S.Ct. 1426, 1433 (2013). We have since

reconciled our holding that uncertain damages cannot destroy

class certification with Comcast’s holding that plaintiffs must

show that their damages are capable of classwide

measurement. In Leyva, we reaffirmed that uncertain

damages calculations alone cannot defeat class certification

because Comcast stood only for the proposition that

“plaintiffs must be able to show that their damages stemmed

from the defendant’s actions that created the legal liability.” 

Leyva, 716 F.3d at 513–14.

Uncertainty regarding class members’ damages does not

prevent certification of a class as long as a valid method has

been proposed for calculating those damages. Id. at 514; see

also Alaska Rent-A-Car, Inc. v. Avis Budget Grp., Inc.,

738 F.3d 960, 970 (9th Cir. 2013) (explaining that the law

“requires onlythat damages be capable of measurement based

upon reliable factors without undue speculation”). “[T]he
LAMBERT V. NUTRACEUTICAL CORP. 23

fact that the amount of damage may not be susceptible of

exact proof or may be uncertain, contingent or difficult of

ascertainment does not bar recovery.” Pulaski, 802 F.3d at

989 (quoting Marsu, B.V. v. Walt Disney Co., 185 F.3d 932,

939 (9th Cir.1999)); see also Just Film, Inc. v. Buono,

847 F.3d 1108, 1121 (9th Cir. 2017) (reaffirming that so long

as the proposed damages model is attributable to the

plaintiff’s legal theory of the harm, and damages can be

determined without excessive difficulty, decertification is not

warranted).

Class wide damages calculations under the UCL, FAL,

and CLRA are particularly forgiving. California law

“requires only that some reasonable basis of computation of

damages be used, and the damages may be computed even if

the result reached is an approximation.” Pulaski, 802 F.3d at

989 (quoting Marsu, 185 F.3d at 938–39) (referring to the

UCL and FAL); see also Wiener v. Dannon Co., 255 F.R.D.

658, 670 (C.D. Cal. 2009) (providing that courts also have

“‘very broad’ discretion to determine” damages under the

CLRA); Colgan v. Leatherman Tool Grp., Inc., 38 Cal. Rptr.

3d 36, 61 (Cal. Ct. App. 2006) (explaining that damages

under the UCL and FAL “must be of a measurable amount to

restore to the plaintiff what has been acquired by violations

of the statutes, and that measurable amount must be supported

by evidence”). Under California law, because restitution

“damages may be computed even if the result reached is an

approximation,” GHK Assocs. v. Mayer Grp., Inc., 274 Cal.

Rptr. 168, 179 (Cal. Ct. App. 1990), uncertain damages

should not prevent class certification, B.W.I.Custom Kitchen

v. Owens-Illinois, Inc., 235 Cal.Rptr. 228, 237 (Cal. Ct. App.

1987) (“[W]e know of no case where [factual determinations

of damages] ha[ve] prevented a court from aiding the class to

obtain its just restitution.”).
24 LAMBERT V. NUTRACEUTICAL CORP.

Lambert proposed measuring class wide damages under

the full refund model. The full refund model measures

damages by presuming a full refund for each customer, on the

basis that the product has no or only a de minimis value. FTC

v. Figgie Int’l, Inc., 994 F.2d 595, 606 (9th Cir. 1993)

(“Customers who purchased rhinestones sold as diamonds

should have the opportunity to get all of their money back.”). 

Here, Lambert presented evidence that the product at issue

was valueless and therefore amenable to full refund

treatment. We agree with the district court that the full

refund model is consistent with Lambert’s theory of liability. 

Accordingly, Lambert was required only to show that the full

price amount of retail sales of the product could be

approximated over the relevant time period, even if that

figure or the data supporting it—in this case the average retail

price multiplied by the number of units sold—was uncertain.9

Leyva, 716 F.3d at 514.

Although Lambert did not present evidence of the actual

average retail price, he did present evidence of both unit sales

and the suggested retail price over the relevant time period.10

There may well be additional evidence that Lambert could

present at trial to support an average retail price. For

9 This is not to say that every case proceeding under a full refund

theory must produce figures for the average price and unit sales of a

product. As Lambert argued in his motion for class certification, point-ofsale data approximating the total retail expenditure would also be an

appropriate method of calculating restitution on a worthless item. So, too,

would evidence of the defendant’s wholesale revenue, if reasonably

capable of being weighed or adjusted by the trier of fact to account for

possible difference between wholesale and retail values.

10 Notably, the suggested retail price was cited as one of the original

grounds for certifying the class.
LAMBERT V. NUTRACEUTICAL CORP. 25

example, the record contains evidence that Lambert paid

$16–$18 per 30-count bottle of the product and that

Nutraceutical, through its website, sold 30-count bottles for

$14.39 during this time frame. The suggested retail price in

conjunction with Lambert’s other evidence suggests that a

trier of fact could calculate or sufficiently approximate the

average retail price for the product.

We recognize that a suggested retail price does not

“automatically configure an average,” but such a precise

average is unnecessary for class certification. At this stage,

the question is only whether Lambert has presented a

workable method. We conclude that he has.

Accordingly, becauseLambert’s damages model matched

his theory of liability, and because Lambert had shown that

his damages model was supportable on evidence that could be

introduced at trial, the class should not have been decertified. 

The district court abused its discretion in holding otherwise,

contrary to our law. See Hinkson, 585 F.3d at 1261–62

(holding that legal error is an abuse of discretion); see also

Pulaski, 802 F.3d at 989; Leyva, 716 F.3d at 513–14;

Yokoyama, 594 F.3d at 1094. Whether Lambert could prove

damages to a reasonable certainty on the basis of his full

refund model is a question of fact that should be decided at

trial.11

11 Because we hold that Lambert showed damages sufficient to avoid

decertification under the full refund model, we need not reach the question

of whether he waived his non-restitutionary disgorgement argument, or

whether that arguments fails on the merits.
26 LAMBERT V. NUTRACEUTICAL CORP.

V.

For the foregoing reasons, we conclude that Lambert’s

Rule 23(f) petition was timely, reverse the district court’s

order decertifying the class, and remand for further

proceedings consistent with this opinion.

REVERSED AND REMANDED.