(Slip Opinion) OCTOBER TERM, 2009 1 

Syllabus 

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is

being done in connection with this case, at the time the opinion is issued.

The syllabus constitutes no part of the opinion of the Court but has been

prepared by the Reporter of Decisions for the convenience of the reader. 

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337. 

SUPREME COURT OF THE UNITED STATES 

Syllabus 

SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. v. 

ALLSTATE INSURANCE CO. 

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR 

THE SECOND CIRCUIT 

No. 08–1008. Argued November 2, 2009—Decided March 31, 2010 

After respondent Allstate refused to remit the interest due under New 

York law on petitioner Shady Grove’s insurance claim, Shady Grove 

filed this class action in diversity to recover interest Allstate owed it

and others. Despite the class action provisions set forth in Federal 

Rule of Civil Procedure 23, the District Court held itself deprived of 

jurisdiction by N. Y. Civ. Prac. Law Ann. §901(b), which precludes a

class action to recover a “penalty” such as statutory interest. Affirming, the Second Circuit acknowledged that a Federal Rule adopted in

compliance with the Rules Enabling Act, 28 U. S. C. §2072, would 

control if it conflicted with §901(b), but held there was no conflict because §901(b) and Rule 23 address different issues—eligibility of the 

particular type of claim for class treatment and certifiability of a

given class, respectively. Finding no Federal Rule on point, the Court 

of Appeals held that §901(b) must be applied by federal courts sitting

in diversity because it is “substantive” within the meaning of Erie R. 

Co. v. Tompkins, 304 U. S. 64 (1938). 

Held: The judgment is reversed, and the case is remanded. 

549 F. 3d 137, reversed and remanded. 

JUSTICE SCALIA delivered the opinion of the Court with respect to 

PARTS I and II–A, concluding that §901(b) does not preclude a federal 

district court sitting in diversity from entertaining a class action under Rule 23. Pp. 3–12.

(a) If Rule 23 answers the question in dispute, it governs here 

unless it exceeds its statutory authorization or Congress’s rulemaking power. Burlington Northern R. Co. v. Woods, 480 U. S. 1, 4–5. 

Pp. 3–4. 
2 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Syllabus 

(b) Rule 23(b) answers the question in dispute—whether Shady 

Grove’s suit may proceed as a class action—when it states that “[a]

class action may be maintained” if certain conditions are met. Since 

§901(b) attempts to answer the same question, stating that Shady

Grove’s suit “may not be maintained as a class action” because of the

relief it seeks, that provision cannot apply in diversity suits unless

Rule 23 is ultra vires. The Second Circuit’s view that §901(b) and

Rule 23 address different issues is rejected. The line between eligibility and certifiability is entirely artificial and, in any event, Rule 23

explicitly empowers a federal court to certify a class in every case

meeting its criteria. Allstate’s arguments based on the exclusion of

some federal claims from Rule 23’s reach pursuant to federal statutes

and on §901’s structure are unpersuasive. Pp. 4–6.

(c) The dissent’s claim that §901(b) can coexist with Rule 23 because it addresses only the remedy available to class plaintiffs is

foreclosed by §901(b)’s text, notwithstanding its perceived purpose. 

The principle that courts should read ambiguous Federal Rules to

avoid overstepping the authorizing statute, 28 U. S. C. §2072(b), does

not apply because Rule 23 is clear. The dissent’s approach does not 

avoid a conflict between §901(b) and Rule 23 but instead would render Rule 23 partially invalid. Pp. 6–12.

JUSTICE SCALIA, joined by THE CHIEF JUSTICE, JUSTICE THOMAS, and 

JUSTICE SOTOMAYOR, concluded in Parts II–B and II–D: 

(a) The Rules Enabling Act, 28 U. S. C. §2072, not Erie, controls 

the validity of a Federal Rule of Procedure. Section 2072(b)’s requirement that federal procedural rules “not abridge, enlarge or modify any substantive right” means that a Rule must “really regulat[e]

procedure,—the judicial process for enforcing rights and duties recognized by substantive law and for justly administering remedy and 

redress for disregard or infraction of them,” Sibbach v. Wilson & Co., 

312 U. S. 1, 14. Though a Rule may incidentally affect a party’s 

rights, it is valid so long as it regulates only the process for enforcing

those rights, and not the rights themselves, the available remedies,

or the rules of decision for adjudicating either. Rule 23 satisfies that 

criterion, at least insofar as it allows willing plaintiffs to join their 

separate claims against the same defendants. Allstate’s arguments 

asserting §901(b)’s substantive impact are unavailing: It is not the

substantive or procedural nature of the affected state law that matters, but that of the Federal Rule. See, e.g., id., at 14. Pp. 12–16.

(b) Opening federal courts to class actions that cannot proceed in 

state court will produce forum shopping, but that is the inevitable result of the uniform system of federal procedure that Congress created. P. 22. 

JUSTICE SCALIA, joined by THE CHIEF JUSTICE and JUSTICE THOMAS, 
Cite as: 559 U. S. ____ (2010) 3 

Syllabus 

concluded in Part II–C that the concurrence’s analysis—under which

a Federal Rule may displace a state procedural rule that is not

“bound up” or “sufficiently intertwined” with substantive rights and

remedies under state law—squarely conflicts with Sibbach’s single 

criterion that the Federal Rule “really regulat[e] procedure,” 312 

U. S., at 13–14. Pp. 16–22.

JUSTICE STEVENS agreed that Federal Rule of Civil Procedure 23

must apply because it governs whether a class must be certified, and

it does not violate the Rules Enabling Act in this case. Pp. 1–22.

(a) When the application of a federal rule would “abridge, 

enlarge or modify any substantive right,” 28 U. S. C. §2072(b), the

federal rule cannot govern. In rare cases, a federal rule that dictates 

an answer to a traditionally procedural question could, if applied,

displace an unusual state law that is procedural in the ordinary use 

of the term but is so intertwined with a state right or remedy that it

functions to define the scope of the state-created right. Examples

may include state laws that make it significantly more difficult to

bring or to prove a claim or that function as limits on the amount of 

recovery. An application of a federal rule that directly collides with

such a state law violates the Rules Enabling Act. Pp. 1–13.

(b) N. Y. Civ. Prac. Law Ann. §901(b), however, is not such a

state law. It is a procedural rule that is not part of New York’s substantive law. Pp. 17–22. 

SCALIA, J., announced the judgment of the Court and delivered the 

opinion of the Court with respect to Parts I and II–A, in which ROBERTS, C. J., and STEVENS, THOMAS, and SOTOMAYOR, JJ., joined, an opinion with respect to Parts II–B and II–D, in which ROBERTS, C. J., and 

THOMAS, and SOTOMAYOR, JJ., joined, and an opinion with respect to 

Part II–C, in which ROBERTS, C. J., and, THOMAS, J., joined. STEVENS, 

J., filed an opinion concurring in part and concurring in the judgment. 

GINSBURG, J., filed a dissenting opinion, in which KENNEDY, BREYER, 

and ALITO, JJ., joined. 
_________________ 

_________________ 

Cite as: 559 U. S. ____ (2010) 1 

Opinion of SCALIA, J. 

NOTICE: This opinion is subject to formal revision before publication in the 

preliminary print of the United States Reports. Readers are requested to

notify the Reporter of Decisions, Supreme Court of the United States, Washington, D. C. 20543, of any typographical or other formal errors, in order

that corrections may be made before the preliminary print goes to press. 

SUPREME COURT OF THE UNITED STATES 

No. 08–1008 

SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A., 

PETITIONER v. ALLSTATE INSURANCE 

COMPANY

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE SECOND CIRCUIT

[March 31, 2010]

 JUSTICE SCALIA announced the judgment of the Court

and delivered the opinion of the Court with respect to

Parts I and II–A, an opinion with respect to Parts II–B 

and II–D, in which THE CHIEF JUSTICE, JUSTICE THOMAS, 

and JUSTICE SOTOMAYOR join, and an opinion with respect 

to Part II–C, in which THE CHIEF JUSTICE and JUSTICE 

THOMAS join. 

New York law prohibits class actions in suits seeking 

penalties or statutory minimum damages.1 We consider 

—————— 

1N. Y. Civ. Prac. Law Ann. §901 (West 2006) provides: 

“(a) One or more members of a class may sue or be sued as representative parties on behalf of all if: 

“1. the class is so numerous that joinder of all members, whether 

otherwise required or permitted, is impracticable; 

“2. there are questions of law or fact common to the class which 

predominate over any questions affecting only individual members; 

“3. the claims or defenses of the representative parties are typical of 

the claims or defenses of the class; 

“4. the representative parties will fairly and adequately protect the 

interests of the class; and 

“5. a class action is superior to other available methods for the fair 
Opinion of SCALIA, J. 

2 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of the Court 

whether this precludes a federal district court sitting in 

diversity from entertaining a class action under Federal

Rule of Civil Procedure 23.2 

I 

The petitioner’s complaint alleged the following: Shady

Grove Orthopedic Associates, P. A., provided medical care 

to Sonia E. Galvez for injuries she suffered in an automobile accident. As partial payment for that care, Galvez

assigned to Shady Grove her rights to insurance benefits

under a policy issued in New York by Allstate Insurance

Co. Shady Grove tendered a claim for the assigned benefits to Allstate, which under New York law had 30 days to 

pay the claim or deny it. See N. Y. Ins. Law Ann. §5106(a) 

(West 2009). Allstate apparently paid, but not on time,

and it refused to pay the statutory interest that accrued on

the overdue benefits (at two percent per month), see ibid. 

Shady Grove filed this diversity suit in the Eastern 

District of New York to recover the unpaid statutory interest. Alleging that Allstate routinely refuses to pay 

—————— 

and efficient adjudication of the controversy. 

“(b) Unless a statute creating or imposing a penalty, or a minimum 

measure of recovery specifically authorizes the recovery thereof in a 

class action, an action to recover a penalty, or minimum measure of 

recovery created or imposed by statute may not be maintained as a

class action.” 2Rule 23(a) provides: 

“(a) Prerequisites. One or more members of a class may sue or be

sued as representative parties on behalf of all members only if: 

“(1) the class is so numerous that joinder of all members is impracticable; 

“(2) there are questions of law or fact common to the class; 

“(3) the claims or defenses of the representative parties are typical

of the claims or defenses of the class; and 

“(4) the representative parties will fairly and adequately protect

the interests of the class.” 

Subsection (b) says that “[a] class action may be maintained if Rule 23

(a) is satisfied and if” the suit falls into one of three described categories (irrelevant for present purposes). 
Opinion of SCALIA, J. 

Cite as: 559 U. S. ____ (2010) 3 

Opinion of the Court 

interest on overdue benefits, Shady Grove sought relief on 

behalf of itself and a class of all others to whom Allstate 

owes interest. The District Court dismissed the suit for 

lack of jurisdiction. 466 F. Supp. 2d 467 (2006). It reasoned that N. Y. Civ. Prac. Law Ann. §901(b), which precludes a suit to recover a “penalty” from proceeding as a 

class action, applies in diversity suits in federal court, 

despite Federal Rule of Civil Procedure 23. Concluding

that statutory interest is a “penalty” under New York law, 

it held that §901(b) prohibited the proposed class action.

And, since Shady Grove conceded that its individual claim

(worth roughly $500) fell far short of the amount-incontroversy requirement for individual suits under 28

U. S. C. §1332(a), the suit did not belong in federal court.3 

The Second Circuit affirmed. 549 F. 3d 137 (2008). The 

court did not dispute that a federal rule adopted in compliance with the Rules Enabling Act, 28 U. S. C. §2072,

would control if it conflicted with §901(b). But there was 

no conflict because (as we will describe in more detail 

below) the Second Circuit concluded that Rule 23 and 

§901(b) address different issues. Finding no federal rule 

on point, the Court of Appeals held that §901(b) is “substantive” within the meaning of Erie R. Co. v. Tompkins, 

304 U. S. 64 (1938), and thus must be applied by federal

courts sitting in diversity. 

We granted certiorari, 556 U. S. ___ (2009). 

II 

The framework for our decision is familiar. We must 

first determine whether Rule 23 answers the question in

dispute. Burlington Northern R. Co. v. Woods, 480 U. S. 1, 

—————— 

3Shady Grove had asserted jurisdiction under 28 U. S. C. §1332(d)(2), 

which relaxes, for class actions seeking at least $5 million, the rule 

against aggregating separate claims for calculation of the amount in 

controversy. See Exxon Mobil Corp. v. Allapattah Services, Inc., 545 

U. S. 546, 571 (2005). 
Opinion of SCALIA, J. 

4 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of the Court 

4–5 (1987). If it does, it governs—New York’s law notwithstanding—unless it exceeds statutory authorization or 

Congress’s rulemaking power. Id., at 5; see Hanna v. 

Plumer, 380 U. S. 460, 463–464 (1965). We do not wade 

into Erie’s murky waters unless the federal rule is inapplicable or invalid. See 380 U. S., at 469–471. 

A 

The question in dispute is whether Shady Grove’s suit 

may proceed as a class action. Rule 23 provides an answer. It states that “[a] class action may be maintained” if 

two conditions are met: The suit must satisfy the criteria

set forth in subdivision (a) (i.e., numerosity, commonality,

typicality, and adequacy of representation), and it also

must fit into one of the three categories described in subdivision (b). Fed. Rule Civ. Proc. 23(b). By its terms this

creates a categorical rule entitling a plaintiff whose suit

meets the specified criteria to pursue his claim as a class

action. (The Federal Rules regularly use “may” to confer 

categorical permission, see, e.g., Fed. Rules Civ. Proc. 

8(d)(2)–(3), 14(a)(1), 18(a)–(b), 20(a)(1)–(2), 27(a)(1),

30(a)(1), as do federal statutes that establish procedural 

entitlements, see, e.g., 29 U. S. C. §626(c)(1); 42 U. S. C. 

§2000e–5(f)(1).) Thus, Rule 23 provides a one-size-fits-all 

formula for deciding the class-action question. Because 

§901(b) attempts to answer the same question—i.e., it 

states that Shady Grove’s suit “may not be maintained as 

a class action” (emphasis added) because of the relief it 

seeks—it cannot apply in diversity suits unless Rule 23 is

ultra vires. 

The Second Circuit believed that §901(b) and Rule 23 do

not conflict because they address different issues. Rule 23, 

it said, concerns only the criteria for determining whether

a given class can and should be certified; section 901(b), on

the other hand, addresses an antecedent question:

whether the particular type of claim is eligible for class 
Opinion of SCALIA, J. 

Cite as: 559 U. S. ____ (2010) 5 

Opinion of the Court 

treatment in the first place—a question on which Rule 23

is silent. See 549 F. 3d, at 143–144. Allstate embraces 

this analysis. Brief for Respondent 12–13.

We disagree. To begin with, the line between eligibility 

and certifiability is entirely artificial. Both are preconditions for maintaining a class action. Allstate suggests that

eligibility must depend on the “particular cause of action” 

asserted, instead of some other attribute of the suit, id., at 

12. But that is not so. Congress could, for example, provide that only claims involving more than a certain number of plaintiffs are “eligible” for class treatment in federal 

court. In other words, relabeling Rule 23(a)’s prerequisites “eligibility criteria” would obviate Allstate’s objection—a sure sign that its eligibility-certifiability distinction is made-to-order. 

There is no reason, in any event, to read Rule 23 as

addressing only whether claims made eligible for class

treatment by some other law should be certified as class 

actions. Allstate asserts that Rule 23 neither explicitly

nor implicitly empowers a federal court “to certify a class

in each and every case” where the Rule’s criteria are met. 

Id., at 13–14. But that is exactly what Rule 23 does: It 

says that if the prescribed preconditions are satisfied “[a] 

class action may be maintained” (emphasis added)—not “a 

class action may be permitted.” Courts do not maintain 

actions; litigants do. The discretion suggested by Rule 23’s

“may” is discretion residing in the plaintiff: He may bring

his claim in a class action if he wishes. And like the rest 

of the Federal Rules of Civil Procedure, Rule 23 automatically applies “in all civil actions and proceedings in the 

United States district courts,” Fed. Rule Civ. Proc. 1. See 

Califano v. Yamasaki, 442 U. S. 682, 699–700 (1979). 

Allstate points out that Congress has carved out some

federal claims from Rule 23’s reach, see, e.g., 8 U. S. C. 

§1252(e)(1)(B)—which shows, Allstate contends, that Rule

23 does not authorize class actions for all claims, but 
Opinion of SCALIA, J. 

6 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of the Court 

rather leaves room for laws like §901(b). But Congress,

unlike New York, has ultimate authority over the Federal 

Rules of Civil Procedure; it can create exceptions to an 

individual rule as it sees fit—either by directly amending 

the rule or by enacting a separate statute overriding it in 

certain instances. Cf. Henderson v. United States, 517 

U. S. 654, 668 (1996). The fact that Congress has created 

specific exceptions to Rule 23 hardly proves that the Rule

does not apply generally. In fact, it proves the opposite. If 

Rule 23 did not authorize class actions across the board, 

the statutory exceptions would be unnecessary. 

Allstate next suggests that the structure of §901 shows 

that Rule 23 addresses only certifiability. Section 901(a),

it notes, establishes class-certification criteria roughly

analogous to those in Rule 23 (wherefore it agrees that 

subsection is pre-empted). But §901(b)’s rule barring class

actions for certain claims is set off as its own subsection, 

and where it applies §901(a) does not. This shows, according to Allstate, that §901(b) concerns a separate subject. 

Perhaps it does concern a subject separate from the subject of §901(a). But the question before us is whether it 

concerns a subject separate from the subject of Rule 23— 

and for purposes of answering that question the way New

York has structured its statute is immaterial. Rule 23 

permits all class actions that meet its requirements, and a

State cannot limit that permission by structuring one part 

of its statute to track Rule 23 and enacting another part 

that imposes additional requirements. Both of §901’s

subsections undeniably answer the same question as Rule

23: whether a class action may proceed for a given suit. 

Cf. Burlington, 480 U. S., at 7–8. 

The dissent argues that §901(b) has nothing to do with

whether Shady Grove may maintain its suit as a class 

action, but affects only the remedy it may obtain if it wins.

See post, at 8–17 (opinion of GINSBURG, J.). Whereas 

“Rule 23 governs procedural aspects of class litigation” by 
Opinion of SCALIA, J. 

Cite as: 559 U. S. ____ (2010) 7 

Opinion of the Court 

“prescrib[ing] the considerations relevant to class certification and postcertification proceedings,” §901(b) addresses

only “the size of a monetary award a class plaintiff may 

pursue.” Post, at 11–12. Accordingly, the dissent says, 

Rule 23 and New York’s law may coexist in peace. 

We need not decide whether a state law that limits the 

remedies available in an existing class action would conflict with Rule 23; that is not what §901(b) does. By its

terms, the provision precludes a plaintiff from “maintain[ing]” a class action seeking statutory penalties. 

Unlike a law that sets a ceiling on damages (or puts other 

remedies out of reach) in properly filed class actions, 

§901(b) says nothing about what remedies a court may 

award; it prevents the class actions it covers from coming

into existence at all.4 Consequently, a court bound by

§901(b) could not certify a class action seeking both statutory penalties and other remedies even if it announces in

advance that it will refuse to award the penalties in the

event the plaintiffs prevail; to do so would violate the 

statute’s clear prohibition on “maintain[ing]” such suits as

class actions. 

The dissent asserts that a plaintiff can avoid §901(b)’s

barrier by omitting from his complaint (or removing) a 

request for statutory penalties. See post, at 14–15. Even 

assuming all statutory penalties are waivable,5 the fact 

—————— 

4Contrary to the dissent’s implication, post, at 13, we express no view

as to whether state laws that set a ceiling on damages recoverable in a

single suit, see App. A to Brief for Respondent, are pre-empted. 

Whether or not those laws conflict with Rule 23, §901(b) does conflict

because it addresses not the remedy, but the procedural right to maintain a class action. As Allstate and the dissent note, several federal 

statutes also limit the recovery available in class actions. See, e.g., 12 

U. S. C. §2605(f)(2)(B); 15 U. S. C. §1640(a)(2)(B); 29 U. S. C. 

§1854(c)(1). But Congress has plenary power to override the Federal

Rules, so its enactments, unlike those of the States, prevail even in case

of a conflict. 5But see, e.g., Asher v. Abbott Labs., 290 App. Div. 2d 208, 737 
Opinion of SCALIA, J. 

8 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of the Court 

that a complaint omitting them could be brought as a class

action would not at all prove that §901(b) is addressed 

only to remedies. If the state law instead banned class 

actions for fraud claims, a would-be class-action plaintiff 

could drop the fraud counts from his complaint and proceed with the remainder in a class action. Yet that would 

not mean the law provides no remedy for fraud; the ban

would affect only the procedural means by which the 

remedy may be pursued. In short, although the dissent

correctly abandons Allstate’s eligibility-certifiability distinction, the alternative it offers fares no better. 

The dissent all but admits that the literal terms of 

§901(b) address the same subject as Rule 23—i.e., whether 

a class action may be maintained—but insists the provision’s purpose is to restrict only remedies. See post, at 12– 

15; post, at 15 (“[W]hile phrased as responsive to the

question whether certain class actions may begin, §901(b) 

is unmistakably aimed at controlling how those actions

must end”). Unlike Rule 23, designed to further procedural fairness and efficiency, §901(b) (we are told) “responds to an entirely different concern”: the fear that 

allowing statutory damages to be awarded on a class-wide

basis would “produce overkill.” Post, at 12, 9 (internal 

quotation marks omitted). The dissent reaches this conclusion on the basis of (1) constituent concern recorded in 

the law’s bill jacket; (2) a commentary suggesting that the 

Legislature “apparently fear[ed]” that combining class 

actions and statutory penalties “could result in annihilating punishment of the defendant,” V. Alexander, Practice 

Commentaries, C901:11, reprinted in 7B McKinney’s

Consolidated Laws of New York Ann., p. 104 (2006) (internal quotation marks omitted); (3) a remark by the

Governor in his signing statement that §901(b) “ ‘provides 

—————— 

N. Y. S. 2d 4 (2002) (treble damages under N. Y. Gen. Bus. Law §340(5)

are nonwaivable, wherefore class actions under that law are barred). 
Opinion of SCALIA, J. 

Cite as: 559 U. S. ____ (2010) 9 

Opinion of the Court 

a controlled remedy,’” post, at 9 (quoting Memorandum on 

Approving L. 1975, Ch. 207, reprinted in 1975 N. Y. Laws,

at 1748; emphasis deleted), and (4) a state court’s statement that the final text of §901(b) “‘was the result of a 

compromise among competing interests,’” post, at 9 (quoting Sperry v. Crompton Corp., 8 N. Y. 3d 204, 211, 863 

N. E. 2d 1012, 1015 (2007)). 

This evidence of the New York Legislature’s purpose is 

pretty sparse. But even accepting the dissent’s account of

the Legislature’s objective at face value, it cannot override

the statute’s clear text. Even if its aim is to restrict the 

remedy a plaintiff can obtain, §901(b) achieves that end by 

limiting a plaintiff’s power to maintain a class action. The 

manner in which the law “could have been written,” post, 

at 23, has no bearing; what matters is the law the Legislature did enact. We cannot rewrite that to reflect our 

perception of legislative purpose, see Oncale v. Sundowner 

Offshore Services, Inc., 523 U. S. 75, 79–80 (1998).6 The 

dissent’s concern for state prerogatives is frustrated 

rather than furthered by revising state laws when a po­

—————— 

6Our decision in Walker v. Armco Steel Corp., 446 U. S. 740 (1980), 

discussed by the dissent, post, at 5–6, 13–14, n. 8, is not to the contrary. 

There we held that Rule 3 (which provides that a federal civil action is

“ ‘commenced’ ” by filing a complaint in federal court) did not displace a

state law providing that “ ‘[a]n action shall be deemed commenced, 

within the meaning of this article [the statute of limitations], as to each 

defendant, at the date of the summons which is served on him . . . .’ ” 

446 U. S., at 743, n. 4 (quoting Okla. Stat., Tit. 12, §97 (1971); alteration in original, emphasis added). Rule 3, we explained, “governs the

date from which various timing requirements of the Federal Rules 

begin to run, but does not affect state statutes of limitations” or tolling

rules, which it did not “purpor[t] to displace.” 446 U. S., at 751, 750. 

The texts were therefore not in conflict. While our opinion observed 

that the State’s actual-service rule was (in the State’s judgment) an

“integral part of the several policies served by the statute of limitations,” id., at 751, nothing in our decision suggested that a federal court

may resolve an obvious conflict between the texts of state and federal

rules by resorting to the state law’s ostensible objectives. 
Opinion of SCALIA, J. 

10 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of the Court 

tential conflict with a Federal Rule arises; the statefriendly approach would be to accept the law as written

and test the validity of the Federal Rule.

The dissent’s approach of determining whether state

and federal rules conflict based on the subjective intentions of the state legislature is an enterprise destined to

produce “confusion worse confounded,” Sibbach v. Wilson 

& Co., 312 U. S. 1, 14 (1941). It would mean, to begin 

with, that one State’s statute could survive pre-emption 

(and accordingly affect the procedures in federal court)

while another State’s identical law would not, merely 

because its authors had different aspirations. It would 

also mean that district courts would have to discern, in 

every diversity case, the purpose behind any putatively 

pre-empted state procedural rule, even if its text squarely 

conflicts with federal law. That task will often prove

arduous. Many laws further more than one aim, and the 

aim of others may be impossible to discern. Moreover, to 

the extent the dissent’s purpose-driven approach depends 

on its characterization of §901(b)’s aims as substantive, it

would apply to many state rules ostensibly addressed to 

procedure. Pleading standards, for example, often embody 

policy preferences about the types of claims that should

succeed—as do rules governing summary judgment, pretrial discovery, and the admissibility of certain evidence. 

Hard cases will abound. It is not even clear that a state 

supreme court’s pronouncement of the law’s purpose

would settle the issue, since existence of the factual predicate for avoiding federal pre-emption is ultimately a federal question. Predictably, federal judges would be condemned to poring through state legislative history—which

may be less easily obtained, less thorough, and less familiar than its federal counterpart, see R. Mersky & D. Dunn, 

Fundamentals of Legal Research 233 (8th ed. 2002); Torres & Windsor, State Legislative Histories: A Select, Annotated Bibliography, 85 L. Lib. J. 545, 547 (1993). 
Opinion of SCALIA, J. 

Cite as: 559 U. S. ____ (2010) 11 

Opinion of the Court 

But while the dissent does indeed artificially narrow the

scope of §901(b) by finding that it pursues only substantive policies, that is not the central difficulty of the dissent’s position. The central difficulty is that even artificial

narrowing cannot render §901(b) compatible with Rule 23. 

Whatever the policies they pursue, they flatly contradict

each other. Allstate asserts (and the dissent implies, see 

post, at 3, 11) that we can (and must) interpret Rule 23 in 

a manner that avoids overstepping its authorizing statute.7 If the Rule were susceptible of two meanings—one 

that would violate §2072(b) and another that would not—

we would agree. See Ortiz v. Fibreboard Corp., 527 U. S. 

815, 842, 845 (1999); cf. Semtek Int’l Inc. v. Lockheed 

Martin Corp., 531 U. S. 497, 503–504 (2001). But it is not. 

Rule 23 unambiguously authorizes any plaintiff, in any

federal civil proceeding, to maintain a class action if the

Rule’s prerequisites are met. We cannot contort its text, 

even to avert a collision with state law that might render 

—————— 

7The dissent also suggests that we should read the Federal Rules 

“ ‘with sensitivity to important state interests’ ” and “ ‘to avoid conflict 

with important state regulatory policies.’ ” Post, at 7 (quoting Gasperini 

v. Center for Humanities, Inc., 518 U. S. 415, 427, n. 7, 438, n. 22 

(1996)). The search for state interests and policies that are “important”

is just as standardless as the “important or substantial” criterion we

rejected in Sibbach v. Wilson & Co., 312 U. S. 1, 13–14 (1941), to define

the state-created rights a Federal Rule may not abridge. 

If all the dissent means is that we should read an ambiguous Federal

Rule to avoid “substantial variations [in outcomes] between state and

federal litigation,” Semtek Int’l Inc. v. Lockheed Martin Corp., 531 U. S. 

497, 504 (2001) (internal quotation marks omitted), we entirely agree. 

We should do so not to avoid doubt as to the Rule’s validity—since a

Federal Rule that fails Erie’s forum-shopping test is not ipso facto 

invalid, see Hanna v. Plumer, 380 U. S. 460, 469–472 (1965)—but

because it is reasonable to assume that “Congress is just as concerned

as we have been to avoid significant differences between state and

federal courts in adjudicating claims,” Stewart Organization, Inc. v. 

Ricoh Corp., 487 U. S. 22, 37–38 (1988) (SCALIA, J., dissenting). The

assumption is irrelevant here, however, because there is only one 

reasonable reading of Rule 23. 
12 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of SCALIA, J. 

it invalid. See Walker v. Armco Steel Corp., 446 U. S. 740, 

750, n. 9 (1980).8 What the dissent’s approach achieves is 

not the avoiding of a “conflict between Rule 23 and 

§901(b),” post, at 17, but rather the invalidation of Rule 23 

(pursuant to §2072(b) of the Rules Enabling Act) to the 

extent that it conflicts with the substantive policies of 

§901. There is no other way to reach the dissent’s destination. We must therefore confront head-on whether Rule 

23 falls within the statutory authorization. 

B 

Erie involved the constitutional power of federal courts

to supplant state law with judge-made rules. In that 

context, it made no difference whether the rule was technically one of substance or procedure; the touchstone was 

whether it “significantly affect[s] the result of a litigation.” 

Guaranty Trust Co. v. York, 326 U. S. 99, 109 (1945). That 

is not the test for either the constitutionality or the statutory validity of a Federal Rule of Procedure. Congress has

undoubted power to supplant state law, and undoubted 

power to prescribe rules for the courts it has created, so

long as those rules regulate matters “rationally capable of

classification” as procedure. Hanna, 380 U. S., at 472. In 

the Rules Enabling Act, Congress authorized this Court to 

promulgate rules of procedure subject to its review, 28

U. S. C. §2072(a), but with the limitation that those rules 

“shall not abridge, enlarge or modify any substantive

right,” §2072(b). 

We have long held that this limitation means that the 

Rule must “really regulat[e] procedure,—the judicial 

—————— 

8The cases chronicled by the dissent, see post, at 3–8, each involved a 

Federal Rule that we concluded could fairly be read not to “control the 

issue” addressed by the pertinent state law, thus avoiding a “direct 

collision” between federal and state law, Walker, 446 U. S., at 749 

(internal quotation marks omitted). But here, as in Hanna, supra, at 

470, a collision is “unavoidable.” 
Cite as: 559 U. S. ____ (2010) 13 

Opinion of SCALIA, J. 

process for enforcing rights and duties recognized by

substantive law and for justly administering remedy and

redress for disregard or infraction of them,” Sibbach, 312 

U. S., at 14; see Hanna, supra, at 464; Burlington, 480 

U. S., at 8. The test is not whether the rule affects a 

litigant’s substantive rights; most procedural rules do. 

Mississippi Publishing Corp. v. Murphree, 326 U. S. 438, 

445 (1946). What matters is what the rule itself regulates:

If it governs only “the manner and the means” by which

the litigants’ rights are “enforced,” it is valid; if it alters

“the rules of decision by which [the] court will adjudicate

[those] rights,” it is not. Id., at 446 (internal quotation 

marks omitted). 

Applying that test, we have rejected every statutory 

challenge to a Federal Rule that has come before us. We 

have found to be in compliance with §2072(b) rules prescribing methods for serving process, see id., at 445–446 

(Fed. Rule Civ. Proc. 4(f)); Hanna, supra, at 463–465 (Fed. 

Rule Civ. Proc. 4(d)(1)), and requiring litigants whose

mental or physical condition is in dispute to submit to 

examinations, see Sibbach, supra, at 14–16 (Fed. Rule

Civ. Proc. 35); Schlagenhauf v. Holder, 379 U. S. 104, 113– 

114 (1964) (same). Likewise, we have upheld rules authorizing imposition of sanctions upon those who file

frivolous appeals, see Burlington, supra, at 8 (Fed. Rule

App. Proc. 38), or who sign court papers without a reasonable inquiry into the facts asserted, see Business Guides, 

Inc. v. Chromatic Communications Enterprises, Inc., 498 

U. S. 533, 551–554 (1991) (Fed. Rule Civ. Proc. 11). Each 

of these rules had some practical effect on the parties’ 

rights, but each undeniably regulated only the process for 

enforcing those rights; none altered the rights themselves, 

the available remedies, or the rules of decision by which

the court adjudicated either. 

Applying that criterion, we think it obvious that rules

allowing multiple claims (and claims by or against multi­
14 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of SCALIA, J. 

ple parties) to be litigated together are also valid. See, 

e.g., Fed. Rules Civ. Proc. 18 (joinder of claims), 20 (joinder

of parties), 42(a) (consolidation of actions). Such rules 

neither change plaintiffs’ separate entitlements to relief 

nor abridge defendants’ rights; they alter only how the

claims are processed. For the same reason, Rule 23—at 

least insofar as it allows willing plaintiffs to join their 

separate claims against the same defendants in a class

action—falls within §2072(b)’s authorization. A class 

action, no less than traditional joinder (of which it is a

species), merely enables a federal court to adjudicate

claims of multiple parties at once, instead of in separate 

suits. And like traditional joinder, it leaves the parties’

legal rights and duties intact and the rules of decision

unchanged.

Allstate contends that the authorization of class actions 

is not substantively neutral: Allowing Shady Grove to sue 

on behalf of a class “transform[s] [the] dispute over a five 

hundred dollar penalty into a dispute over a five million 

dollar penalty.” Brief for Respondent 1. Allstate’s aggregate liability, however, does not depend on whether the 

suit proceeds as a class action. Each of the 1,000-plus 

members of the putative class could (as Allstate acknowledges) bring a freestanding suit asserting his individual

claim. It is undoubtedly true that some plaintiffs who

would not bring individual suits for the relatively small

sums involved will choose to join a class action. That has 

no bearing, however, on Allstate’s or the plaintiffs’ legal

rights. The likelihood that some (even many) plaintiffs 

will be induced to sue by the availability of a class action 

is just the sort of “incidental effec[t]” we have long held

does not violate §2072(b), Mississippi Publishing, supra, 

at 445. 

Allstate argues that Rule 23 violates §2072(b) because

the state law it displaces, §901(b), creates a right that

the Federal Rule abridges—namely, a “substantive 
Cite as: 559 U. S. ____ (2010) 15 

Opinion of SCALIA, J. 

right . . . not to be subjected to aggregated class-action 

liability” in a single suit. Brief for Respondent 31. To 

begin with, we doubt that that is so. Nothing in the text of

§901(b) (which is to be found in New York’s procedural

code) confines it to claims under New York law; and of

course New York has no power to alter substantive rights

and duties created by other sovereigns. As we have said, 

the consequence of excluding certain class actions may be

to cap the damages a defendant can face in a single suit, 

but the law itself alters only procedure. In that respect,

§901(b) is no different from a state law forbidding simple 

joinder. As a fallback argument, Allstate argues that even 

if §901(b) is a procedural provision, it was enacted “for 

substantive reasons,” id., at 24 (emphasis added). Its end 

was not to improve “the conduct of the litigation process

itself” but to alter “the outcome of that process.” Id., at 26. 

The fundamental difficulty with both these arguments is 

that the substantive nature of New York’s law, or its 

substantive purpose, makes no difference. A Federal Rule 

of Procedure is not valid in some jurisdictions and invalid

in others—or valid in some cases and invalid in others— 

depending upon whether its effect is to frustrate a state 

substantive law (or a state procedural law enacted for 

substantive purposes). That could not be clearer in 

Sibbach: 

“The petitioner says the phrase [‘substantive rights’ in

the Rules Enabling Act] connotes more; that by its use 

Congress intended that in regulating procedure this

Court should not deal with important and substantial 

rights theretofore recognized. Recognized where and

by whom? The state courts are divided as to the 

power in the absence of statute to order a physical examination. In a number such an order is authorized 

by statute or rule. . . .

“The asserted right, moreover, is no more important 
16 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of SCALIA, J. 

than many others enjoyed by litigants in District 

Courts sitting in the several states before the Federal 

Rules of Civil Procedure altered and abolished old 

rights or privileges and created new ones in connection with the conduct of litigation. . . . If we were to

adopt the suggested criterion of the importance of the

alleged right we should invite endless litigation and 

confusion worse confounded. The test must be 

whether a rule really regulates procedure . . . .” 312 

U. S., at 13–14 (footnotes omitted). 

Hanna unmistakably expressed the same understanding 

that compliance of a Federal Rule with the Enabling Act is

to be assessed by consulting the Rule itself, and not its

effects in individual applications: 

“[T]he court has been instructed to apply the Federal

Rule, and can refuse to do so only if the Advisory

Committee, this Court, and Congress erred in their

prima facie judgment that the Rule in question transgresses neither the terms of the Enabling Act nor constitutional restrictions.” 380 U. S., at 471. 

In sum, it is not the substantive or procedural nature or

purpose of the affected state law that matters, but the 

substantive or procedural nature of the Federal Rule. We

have held since Sibbach, and reaffirmed repeatedly, that

the validity of a Federal Rule depends entirely upon 

whether it regulates procedure. See Sibbach, supra, at 14; 

Hanna, supra, at 464; Burlington, 480 U. S., at 8. If it 

does, it is authorized by §2072 and is valid in all jurisdictions, with respect to all claims, regardless of its incidental 

effect upon state-created rights. 

C 

A few words in response to the concurrence. We understand it to accept the framework we apply—which requires first, determining whether the federal and state 
Cite as: 559 U. S. ____ (2010) 17 

Opinion of SCALIA, J. 

rules can be reconciled (because they answer different

questions), and second, if they cannot, determining

whether the Federal Rule runs afoul of §2072(b). Post, at 

5–7 (STEVENS, J., concurring in part and concurring in 

judgment). The concurrence agrees with us that Rule 23

and §901(b) conflict, post, at 15–16, and departs from us

only with respect to the second part of the test, i.e., 

whether application of the Federal Rule violates §2072(b), 

post, at 7–13. Like us, it answers no, but for a reason 

different from ours. Post, at 17–22. 

 The concurrence would decide this case on the basis, not 

that Rule 23 is procedural, but that the state law it displaces is procedural, in the sense that it does not “function

as a part of the State’s definition of substantive rights and

remedies.” Post, at 1. A state procedural rule is not preempted, according to the concurrence, so long

as it is “so bound up with,” or “sufficiently intertwined

with,” a substantive state-law right or remedy “that it

defines the scope of that substantive right or remedy,” 

post, at 4, 13. 

This analysis squarely conflicts with Sibbach, which 

established the rule we apply. The concurrence contends 

that Sibbach did not rule out its approach, but that is not 

so. Recognizing the impracticability of a test that turns on

the idiosyncrasies of state law, Sibbach adopted and applied a rule with a single criterion: whether the Federal 

Rule “really regulates procedure.” 312 U. S., at 14.9 That 

—————— 

9The concurrence claims that in Sibbach “[t]he Court . . . had no occasion to consider whether the particular application of the Federal

Rules in question would offend the Enabling Act.” Post, at 12. Had 

Sibbach been applying the concurrence’s theory, that is quite true—

which demonstrates how inconsistent that theory is with Sibbach. For 

conformity with the Rules Enabling Act was the very issue Sibbach

decided: The petitioner’s position was that Rules 35 and 37 exceeded

the Enabling Act’s authorization, 312 U. S., at 9, 13; the Court faced 

and rejected that argument, id., at 13–16, and proceeded to reverse

the lower court for failing to apply Rule 37 correctly, id., at 16. There 
18 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of SCALIA, J. 

the concurrence’s approach would have yielded the same

result in Sibbach proves nothing; what matters is the rule 

we did apply, and that rule leaves no room for special 

exemptions based on the function or purpose of a particular state rule.10 We have rejected an attempt to read into 

Sibbach an exception with no basis in the opinion, see 

Schlagenhauf, 379 U. S., at 113–114, and we see no reason 

to find such an implied limitation today. 

In reality, the concurrence seeks not to apply Sibbach, 

but to overrule it (or, what is the same, to rewrite it). Its 

approach, the concurrence insists, gives short shrift to the 

statutory text forbidding the Federal Rules from 

“abridg[ing], enlarg[ing], or modify[ing] any substantive 

right,” §2072(b). See post, at 9–10. There is something to

that. It is possible to understand how it can be determined whether a Federal Rule “enlarges” substantive 

—————— 

could not be a clearer rejection of the theory that the concurrence now

advocates. 

The concurrence responds that the “the specific question of ‘the 

obligation of federal courts to apply the substantive law of a state’ ” was

not before the Court, post, at 12 (quoting Sibbach, supra, at 9). It is 

clear from the context, however, that this passage referred to the Erie 

prohibition of court-created rules that displace state law. The opinion

unquestionably dealt with the Federal Rules’ compliance with §2072(b),

and it adopted the standard we apply here to resolve the question, 

which does not depend on whether individual applications of the Rule

abridge or modify state-law rights. See 312 U. S., at 13–14. To the 

extent Sibbach did not address the Federal Rules’ validity vis-à-vis

contrary state law, Hanna surely did, see 380 U. S., at 472, and it made 

clear that Sibbach’s test still controls, see 380 U. S., at 464–465, 

470–471. 10The concurrence insists that we have misread Sibbach, since surely 

a Federal Rule that “in most cases” regulates procedure does not do so 

when it displaces one of those “rare” state substantive laws that are 

disguised as rules of procedure. Post, at 13, n. 13. This mistakes what 

the Federal Rule regulates for its incidental effects. As we have explained, supra, at 12–13, most Rules have some effect on litigants’

substantive rights or their ability to obtain a remedy, but that does not 

mean the Rule itself regulates those rights or remedies. 
Cite as: 559 U. S. ____ (2010) 19 

Opinion of SCALIA, J. 

rights without consulting State law: If the Rule creates a

substantive right, even one that duplicates some statecreated rights, it establishes a new federal right. But it is 

hard to understand how it can be determined whether a 

Federal Rule “abridges” or “modifies” substantive rights

without knowing what state-created rights would obtain if 

the Federal Rule did not exist. Sibbach’s exclusive focus 

on the challenged Federal Rule—driven by the very real

concern that Federal Rules which vary from State to State 

would be chaos, see 312 U. S., at 13–14—is hard to square 

with §2072(b)’s terms.11

 Sibbach has been settled law, however, for nearly seven 

decades.12 Setting aside any precedent requires a “special 

—————— 

11The concurrence’s approach, however, is itself unfaithful to the 

statute’s terms. Section 2072(b) bans abridgement or modification only

of “substantive rights,” but the concurrence would prohibit pre-emption 

of “procedural rules that are intimately bound up in the scope of a 

substantive right or remedy,” post, at 19. This would allow States to 

force a wide array of parochial procedures on federal courts so long as

they are “sufficiently intertwined with a state right or remedy.” Post, 

at 13. 12The concurrence implies that Sibbach has slipped into desuetude, 

apparently for lack of sufficient citations. See post, at 13–14, n. 14. We 

are unaware of any rule to the effect that a holding of ours expires if

the case setting it forth is not periodically revalidated. In any event,

the concurrence’s account of our shunning of Sibbach is greatly exaggerated. Hanna did not merely cite the case, but recognized it as

establishing the governing rule. 380 U. S., at 464–465, 470–471. 

Mississippi Publishing Corp. v. Murphree, 326 U. S. 438, 445–446 

(1946), likewise cited Sibbach and applied the same test, examining the 

Federal Rule, not the state law it displaced. True, Burlington Northern 

R. Co. v. Woods, 480 U. S. 1 (1987), and for that matter Business 

Guides, Inc. v. Chromatic Communications Enterprises, Inc., 498 U. S. 

533 (1991), did not cite Sibbach. But both cited and followed Hanna— 

which as noted held out Sibbach as setting forth the governing rule. 

See Burlington Northern, supra, at 5–6, 8; Business Guides, supra, at 

552–554. Thus, while Sibbach itself may appear infrequently in the

U. S. Reports, its rule—and in particular its focus on the Federal Rule

as the proper unit of analysis—is alive and well. 

 In contrast, Hanna’s obscure obiter dictum that a court “need not 
20 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of SCALIA, J. 

justification” beyond a bare belief that it was wrong. 

Patterson v. McLean Credit Union, 491 U. S. 164, 172 

(1989) (internal quotation marks omitted). And a party

seeking to overturn a statutory precedent bears an even

greater burden, since Congress remains free to correct us, 

ibid., and adhering to our precedent enables it do so, see, 

e.g., Finley v. United States, 490 U. S. 545, 556 (1989); 28 

U. S. C. §1367; Exxon Mobil Corp. v. Allapattah Services, 

Inc., 545 U. S. 546, 558 (2005). We do Congress no service

by presenting it a moving target. In all events, Allstate 

has not even asked us to overrule Sibbach, let alone carried its burden of persuading us to do so. Cf. IBP, Inc. v. 

Alvarez, 546 U. S. 21, 32 (2005). Why we should cast

aside our decades-old decision escapes us, especially since 

(as the concurrence explains) that would not affect the 

result.13 

—————— 

wholly blind itself” to a Federal Rule’s effect on a case’s outcome, 380 

U. S., at 473—which the concurrence invokes twice, post, at 8, 13–14, 

n. 14—has never resurfaced in our opinions in the 45 years since its

first unfortunate utterance. Nor does it cast doubt on Sibbach’s 

straightforward test: As the concurrence notes, Hanna cited Sibbach for 

that statement, 380 U. S., at 473, showing it saw no inconsistency

between the two. 13The concurrence is correct, post, at 10, n. 9, that under our disposition any rule that “really regulates procedure,” Sibbach, supra, at 14, 

will pre-empt a conflicting state rule, however “bound up” the latter is

with substantive law. The concurrence is wrong, however, that that 

result proves our interpretation of §2072(b) implausible, post, at 10, 

n. 9. The result is troubling only if one stretches the term “substantive

rights” in §2072(b) to mean not only state-law rights themselves, but

also any state-law procedures closely connected to them. Neither the 

text nor our precedent supports that expansive interpretation. The 

examples the concurrence offers—statutes of limitations, burdens of 

proof, and standards for appellate review of damages awards—do not

make its broad definition of substantive rights more persuasive. They

merely illustrate that in rare cases it may be difficult to determine

whether a rule “really regulates” procedure or substance. If one concludes the latter, there is no pre-emption of the state rule; the Federal

Rule itself is invalid. 
Cite as: 559 U. S. ____ (2010) 21 

Opinion of SCALIA, J. 

 The concurrence also contends that applying Sibbach 

and assessing whether a Federal Rule regulates substance

or procedure is not always easy. See post, at 11, n. 10. 

Undoubtedly some hard cases will arise (though we have 

managed to muddle through well enough in the 69 years

since Sibbach was decided). But as the concurrence acknowledges, post, at 11, the basic difficulty is unavoidable:

The statute itself refers to “substantive right[s],” §2072(b),

so there is no escaping the substance-procedure distinction. What is more, the concurrence’s approach does

nothing to diminish the difficulty, but rather magnifies it

many times over. Instead of a single hard question of 

whether a Federal Rule regulates substance or procedure, 

that approach will present hundreds of hard questions, 

forcing federal courts to assess the substantive or procedural character of countless state rules that may conflict

with a single Federal Rule.14 And it still does not sidestep 

the problem it seeks to avoid. At the end of the day, one

must come face to face with the decision whether or not 

the state policy (with which a putatively procedural state

rule may be “bound up”) pertains to a “substantive right or 

remedy,” post, at 19—that is, whether it is substance or 

procedure.15 The more one explores the alternatives to 

—————— 

The concurrence’s concern would make more sense if many Federal 

Rules that effectively alter state-law rights “bound up with procedures” 

would survive under Sibbach. But as the concurrence concedes, post, at 

11, n. 10, very few would do so. The possible existence of a few outlier 

instances does not prove Sibbach’s interpretation is absurd. Congress

may well have accepted such anomalies as the price of a uniform

system of federal procedure. 14The concurrence argues that its approach is no more “taxing” than

ours because few if any Federal Rules that are “facially valid” under the 

Enabling Act will fail the concurrence’s test. Post, at 11, and n. 10. But 

that conclusion will be reached only after federal courts have considered hundreds of state rules applying the concurrence’s inscrutable 

standard. 15The concurrence insists that the task will be easier if courts can 
22 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of SCALIA, J. 

Sibbach’s rule, the more its wisdom becomes apparent. 

D 

We must acknowledge the reality that keeping the federal-court door open to class actions that cannot proceed in 

state court will produce forum shopping. That is unacceptable when it comes as the consequence of judge-made rules

created to fill supposed “gaps” in positive federal law. See 

Hanna, 380 U. S., at 471–472. For where neither the Constitution, a treaty, nor a statute provides the rule of decision or authorizes a federal court to supply one, “state law 

must govern because there can be no other law.” Ibid.; see 

Clark, Erie’s Constitutional Source, 95 Cal. L. Rev. 1289, 

1302, 1311 (2007). But divergence from state law, with the 

attendant consequence of forum shopping, is the inevitable

(indeed, one might say the intended) result of a uniform

system of federal procedure. Congress itself has created the

possibility that the same case may follow a different course

if filed in federal instead of state court. Cf. Hanna, 380 

U. S., at 472–473. The short of the matter is that a Federal 

Rule governing procedure is valid whether or not it alters 

the outcome of the case in a way that induces forum shopping. To hold otherwise would be to “disembowel either the 

Constitution’s grant of power over federal procedure” or 

Congress’s exercise of it. Id., at 473–474. 

* * * 

The judgment of the Court of Appeals is reversed, and

the case is remanded for further proceedings. 

It is so ordered. 

—————— 

“conside[r] the nature and functions of the state law,” post, at 11, n. 10, 

regardless of the law’s “form,” post, at 4 (emphasis deleted), i.e., what 

the law actually says. We think that amorphous inquiry into the

“nature and functions” of a state law will tend to increase, rather than 

decrease, the difficulty of classifying Federal Rules as substantive or 

procedural. Walking through the concurrence’s application of its test to 

§901(b), post, at 17–22, gives little reason to hope that its approach will

lighten the burden for lower courts. 
_________________ 

_________________ 

Cite as: 559 U. S. ____ (2010) 1 

Opinion of STEVENS, J. 

SUPREME COURT OF THE UNITED STATES 

No. 08–1008 

SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A., 

PETITIONER v. ALLSTATE INSURANCE 

COMPANY

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE SECOND CIRCUIT

[March 31, 2010] 

JUSTICE STEVENS, concurring in part and concurring in 

the judgment. 

The New York law at issue, N. Y. Civ. Prac. Law Ann. 

(CPLR) §901(b) (West 2006), is a procedural rule that is

not part of New York’s substantive law. Accordingly, I 

agree with JUSTICE SCALIA that Federal Rule of Civil 

Procedure 23 must apply in this case and join Parts I and 

II–A of the Court’s opinion. But I also agree with JUSTICE 

GINSBURG that there are some state procedural rules that 

federal courts must apply in diversity cases because they 

function as a part of the State’s definition of substantive

rights and remedies. 

I 

It is a long-recognized principle that federal courts

sitting in diversity “apply state substantive law and federal procedural law.” Hanna v. Plumer, 380 U. S. 460, 465 

(1965).1 This principle is governed by a statutory framework, and the way that it is administered varies depending upon whether there is a federal rule addressed to the 

—————— 

1See also Gasperini v. Center for Humanities, Inc., 518 U. S. 415, 427 

(1996); E. Chemerinsky, Federal Jurisdiction §5.3, p. 327 (5th ed. 2007)

(hereinafter Chemerinsky); 17A J. Moore et al., Moore’s Federal Practice §124.01[1] (3d ed. 2009) (hereinafter Moore). 
2 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

matter. See id., at 469–472. If no federal rule applies, a

federal court must follow the Rules of Decision Act, 28 

U. S. C. §1652, and make the “relatively unguided Erie 

choice,”2 Hanna, 380 U. S., at 471, to determine whether 

the state law is the “rule of decision.” But when a situation is covered by a federal rule, the Rules of Decision Act 

inquiry by its own terms does not apply. See §1652; 

Hanna, 380 U. S., at 471. Instead, the Rules Enabling Act

(Enabling Act) controls. See 28 U. S. C. §2072.

That does not mean, however, that the federal rule 

always governs. Congress has provided for a system of 

uniform federal rules, see ibid., under which federal courts 

sitting in diversity operate as “an independent system for 

administering justice to litigants who properly invoke its 

jurisdiction,” Byrd v. Blue Ridge Rural Elec. Cooperative, 

Inc., 356 U. S. 525, 537 (1958), and not as state-court 

clones that assume all aspects of state tribunals but are 

managed by Article III judges. See Hanna, 380 U. S., at 

473–474. But while Congress may have the constitutional

power to prescribe procedural rules that interfere with

state substantive law in any number of respects, that is 

not what Congress has done. Instead, it has provided in

the Enabling Act that although “[t]he Supreme Court”

may “prescribe general rules of practice and procedure,”

§2072(a), those rules “shall not abridge, enlarge or modify 

any substantive right,” §2072(b). Therefore, “[w]hen a 

situation is covered by one of the Federal Rules, . . . the 

court has been instructed to apply the Federal Rule”

unless doing so would violate the Act or the Constitution. 

Hanna, 380 U. S., at 471. 

Although the Enabling Act and the Rules of Decision 

—————— 

2The Erie choice requires that the court consider “the twin aims of 

the Erie rule: discouragement of forum-shopping and avoidance of 

inequitable administration of the laws.” Hanna v. Plumer, 380 U. S. 

460, 468 (1965); see also Gasperini, 518 U. S., at 427–428 (describing 

Erie inquiry). 
Cite as: 559 U. S. ____ (2010) 3 

Opinion of STEVENS, J. 

Act “say, roughly, that federal courts are to apply state 

‘substantive’ law and federal ‘procedural’ law,” the inquiries are not the same. Ibid.; see also id., at 469–470. The 

Enabling Act does not invite federal courts to engage in 

the “relatively unguided Erie choice,” id., at 471, but 

instead instructs only that federal rules cannot “abridge, 

enlarge or modify any substantive right,” §2072(b). The 

Enabling Act’s limitation does not mean that federal rules 

cannot displace state policy judgments; it means only that 

federal rules cannot displace a State’s definition of its own

rights or remedies. See Sibbach v. Wilson & Co., 312 U. S. 

1, 13–14 (1941) (reasoning that “the phrase ‘substantive 

rights’” embraces only those state rights that are sought 

to be enforced in the judicial proceedings).

Congress has thus struck a balance: “[H]ousekeeping 

rules for federal courts” will generally apply in diversity 

cases, notwithstanding that some federal rules “will inevitably differ” from state rules. Hanna, 380 U. S., at 473. 

But not every federal “rul[e] of practice or procedure,” 

§2072(a), will displace state law. To the contrary, federal 

rules must be interpreted with some degree of “sensitivity 

to important state interests and regulatory policies,” 

Gasperini v. Center for Humanities, Inc., 518 U. S. 415, 

427, n. 7 (1996), and applied to diversity cases against the 

background of Congress’ command that such rules not 

alter substantive rights and with consideration of “the 

degree to which the Rule makes the character and result

of the federal litigation stray from the course it would

follow in state courts,” Hanna, 380 U. S., at 473. This can 

be a tricky balance to implement.3 

It is important to observe that the balance Congress 

—————— 

3See Chemerinsky §5.3, at 321 (observing that courts “have struggled 

to develop an approach that permits uniform procedural rules to be

applied in federal court while still allowing state substantive law to

govern”). 
4 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

has struck turns, in part, on the nature of the state law 

that is being displaced by a federal rule. And in my view,

the application of that balance does not necessarily turn

on whether the state law at issue takes the form of what is 

traditionally described as substantive or procedural. 

Rather, it turns on whether the state law actually is part

of a State’s framework of substantive rights or remedies.

See §2072(b); cf. Hanna, 380 U. S., at 471 (“The line between ‘substance’ and ‘procedure’ shifts as the legal context changes”); Guaranty Trust Co. v. York, 326 U. S. 99, 

108 (1945) (noting that the words “ ‘substance’ ” and “ ‘procedure’ ” “[e]ach impl[y] different variables depending 

upon the particular problem for which [they] are used”). 

Applying this balance, therefore, requires careful interpretation of the state and federal provisions at issue. “The 

line between procedural and substantive law is hazy,” 

Erie R. Co. v. Tompkins, 304 U. S. 64, 92 (1938) (Reed, J., 

concurring), and matters of procedure and matters of 

substance are not “mutually exclusive categories with

easily ascertainable contents,” Sibbach, 312 U. S., at 17 

(Frankfurter, J., dissenting). Rather, “[r]ules which lawyers call procedural do not always exhaust their effect by 

regulating procedure,” Cohen v. Beneficial Industrial Loan 

Corp., 337 U. S. 541, 555 (1949), and in some situations, 

“procedure and substance are so interwoven that rational 

separation becomes well-nigh impossible,” id., at 559 

(Rutledge, J., dissenting). A “state procedural rule,

though undeniably ‘procedural’ in the ordinary sense of

the term,” may exist “to influence substantive outcomes,” 

S. A. Healy Co. v. Milwaukee Metropolitan Sewerage Dist.,

60 F. 3d 305, 310 (CA7 1995) (Posner, J.), and may in

some instances become so bound up with the state-created

right or remedy that it defines the scope of that substantive right or remedy. Such laws, for example, may be

seemingly procedural rules that make it significantly more

difficult to bring or to prove a claim, thus serving to limit 
Cite as: 559 U. S. ____ (2010) 5 

Opinion of STEVENS, J. 

the scope of that claim. See, e.g, Cohen, 337 U. S., at 555 

(state “procedure” that required plaintiffs to post bond 

before suing); Guaranty Trust Co., 326 U. S. 99 (state 

statute of limitations).4 Such “procedural rules” may also

define the amount of recovery. See, e.g., Gasperini, 518 

U. S., at 427 (state procedure for examining jury verdicts 

as means of capping the available remedy); Moore

§124.07[3][a] (listing examples of federal courts’ applying

state laws that affect the amount of a judgment). 

In our federalist system, Congress has not mandated 

that federal courts dictate to state legislatures the form 

that their substantive law must take. And were federal 

courts to ignore those portions of substantive state law 

that operate as procedural devices, it could in many instances limit the ways that sovereign States may define

their rights and remedies. When a State chooses to use a 

traditionally procedural vehicle as a means of defining the 

scope of substantive rights or remedies, federal courts

must recognize and respect that choice. Cf. Ragan v. 

Merchants Transfer & Warehouse Co., 337 U. S. 530, 533 

(1949) (“Since th[e] cause of action is created by local law,

the measure of it is to be found only in local law. . . . 

Where local law qualifies or abridges it, the federal court 

must follow suit”). 

II 

When both a federal rule and a state law appear to 

govern a question before a federal court sitting in diver-

—————— 

4Cf. Milam v. State Farm Mut. Auto. Ins. Co., 972 F. 2d 166, 170 

(CA7 1992) (Posner, J.) (holding that “where a state in furtherance of 

its substantive policy makes it more difficult to prove a particular type 

of state-law claim, the rule by which it does this, even if denominated a 

rule of evidence or cast in evidentiary terms, will be given effect in a 

diversity suit as an expression of state substantive policy”); Moore

§124.09[2] (listing examples of federal courts that apply state evidentiary rules to diversity suits). Other examples include state-imposed 

burdens of proof. 
6 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

sity, our precedents have set out a two-step framework for 

federal courts to negotiate this thorny area. At both steps

of the inquiry, there is a critical question about what the 

state law and the federal rule mean. 

The court must first determine whether the scope of the 

federal rule is “‘sufficiently broad’” to “‘control the issue’” 

before the court, “thereby leaving no room for the operation” of seemingly conflicting state law. See Burlington 

Northern R. Co. v. Woods, 480 U. S. 1, 4–5 (1987); Walker 

v. Armco Steel Corp., 446 U. S. 740, 749–750, and n. 9 

(1980). If the federal rule does not apply or can operate 

alongside the state rule, then there is no “Ac[t] of Congress” governing that particular question, 28 U. S. C. 

§1652, and the court must engage in the traditional Rules 

of Decision Act inquiry under Erie and its progeny. In 

some instances, the “plain meaning” of a federal rule will 

not come into “‘direct collision’” with the state law, and 

both can operate. Walker, 446 U. S., at 750, n. 9, 749. In 

other instances, the rule “when fairly construed,” Burlington Northern R. Co., 480 U. S., at 4, with “sensitivity to 

important state interests and regulatory policies,” 

Gasperini, 518 U. S., at 427, n. 7, will not collide with the 

state law.5 

—————— 

5 I thus agree with JUSTICE GINSBURG, post, at 3–7, that a federal 

rule, like any federal law, must be interpreted in light of many different

considerations, including “sensitivity to important state interests,” post, 

at 7, and “regulatory policies,” post, at 2. See Stewart Organization, 

Inc. v. Ricoh Corp., 487 U. S. 22, 37–38 (1988) (SCALIA, J., dissenting)

(“We should assume . . . when it is fair to do so, that Congress is just as

concerned as we have been to avoid significant differences between 

state and federal courts in adjudicating claims. . . . Thus, in deciding

whether a federal . . . Rule of Procedure encompasses a particular issue,

a broad reading that would create significant disuniformity between

state and federal courts should be avoided if the text permits”). I 

disagree with JUSTICE GINSBURG, however, about the degree to which 

the meaning of federal rules may be contorted, absent congressional 

authorization to do so, to accommodate state policy goals. 
Cite as: 559 U. S. ____ (2010) 7 

Opinion of STEVENS, J. 

If, on the other hand, the federal rule is “sufficiently 

broad to control the issue before the Court,” such that 

there is a “direct collision,” Walker, 446 U. S., at 749–750, 

the court must decide whether application of the federal 

rule “represents a valid exercise” of the “rulemaking authority . . . bestowed on this Court by the Rules Enabling 

Act.” Burlington Northern R. Co., 480 U. S., at 5; see also 

Gasperini, 518 U. S., at 427, n. 7; Hanna, 380 U. S., at 

471–474. That Act requires, inter alia, that federal rules 

“not abridge, enlarge or modify any substantive right.” 28 

U. S. C. §2072(b) (emphasis added). Unlike JUSTICE 

SCALIA, I believe that an application of a federal rule that

effectively abridges, enlarges, or modifies a state-created

right or remedy violates this command. Congress may

have the constitutional power “to supplant state law” with

rules that are “rationally capable of classification as procedure,” ante, at 12 (internal quotation marks omitted),

but we should generally presume that it has not done so. 

Cf. Wyeth v. Levine, 555 U. S. ___, ___ (2009) (slip op., at 8)

(observing that “we start with the assumption” that a

federal statute does not displace a State’s law “unless that 

was the clear and manifest purpose of Congress” (internal

quotation marks omitted)). Indeed, the mandate that 

federal rules “shall not abridge, enlarge or modify any

substantive right” evinces the opposite intent, as does 

Congress’ decision to delegate the creation of rules to this

Court rather than to a political branch, see 19 C. Wright,

A. Miller, & E. Cooper, Federal Practice and Procedure 

§4509, p. 265 (2d ed. 1996) (hereinafter Wright). 

Thus, the second step of the inquiry may well bleed back 

into the first. When a federal rule appears to abridge, 

enlarge, or modify a substantive right, federal courts must

consider whether the rule can reasonably be interpreted to 

avoid that impermissible result. See, e.g., Semtek Int’l Inc. 

v. Lockheed Martin Corp., 531 U. S. 497, 503 (2001) 

(avoiding an interpretation of Federal Rule of Civil Proce-
8 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

dure 41(b) that “would arguably violate the jurisdictional 

limitation of the Rules Enabling Act” contained in 

§2072(b)).6 And when such a “saving” construction is not

possible and the rule would violate the Enabling Act, 

federal courts cannot apply the rule. See 28 U. S. C. 

§2072(b) (mandating that federal rules “shall not” alter

“any substantive right” (emphasis added)); Hanna, 380 

U. S., at 473 (“[A] court, in measuring a Federal Rule 

against the standards contained in the Enabling Act . . . 

need not wholly blind itself to the degree to which the Rule 

makes the character and result of the federal litigation 

stray from the course it would follow in state courts”); see 

also Semtek Int’l Inc., 531 U. S., at 503–504 (noting that if 

state law granted a particular right, “the federal court’s 

extinguishment of that right. . . would seem to violate 

[§2072(b)]”); cf. Statement of Justices Black and Douglas, 

374 U. S. 865, 870 (1963) (observing that federal rules “as 

applied in given situations might have to be declared 

invalid”). A federal rule, therefore, cannot govern a particular case in which the rule would displace a state law 

that is procedural in the ordinary use of the term but is so

intertwined with a state right or remedy that it functions

to define the scope of the state-created right. And absent 

a governing federal rule, a federal court must engage in

the traditional Rules of Decision Act inquiry, under the 

Erie line of cases. This application of the Enabling Act

shows “sensitivity to important state interests,” post, at 7, 

and “regulatory policies,” post, at 2, but it does so as Congress authorized, by ensuring that federal rules that 

—————— 

6See also Ortiz v. Fibreboard Corp., 527 U. S. 815, 842, 845 (1999)

(adopting “limiting construction” of Federal Rule of Civil Procedure 23

that, inter alia, “minimizes potential conflict with the Rules Enabling 

Act”); Amchem Products, Inc. v. Windsor, 521 U. S. 591, 612–613 (1997)

(observing that federal rules “must be interpreted in keeping with the 

Rules Enabling Act, which instructs that rules of procedure ‘shall not 

abridge, enlarge or modify any substantive right’ ”). 
Cite as: 559 U. S. ____ (2010) 9 

Opinion of STEVENS, J. 

ordinarily “prescribe general rules of practice and procedure,” §2072(a), do “not abridge, enlarge or modify any 

substantive right,” §2072(b). 

JUSTICE SCALIA believes that the sole Enabling Act 

question is whether the federal rule “really regulates 

procedure,” ante, at 12, 16, 17, 20, n. 13 (plurality opinion)

(internal quotation marks omitted), which means, apparently, whether it regulates “the manner and the means by

which the litigants’ rights are enforced,” ante, at 13 (internal quotation marks omitted). I respectfully disagree.7 

This interpretation of the Enabling Act is consonant with

the Act’s first limitation to “general rules of practice and 

procedure,” §2072(a). But it ignores the second limitation 

that such rules also “not abridge, enlarge or modify any

substantive right,” §2072(b) (emphasis added),8 and in so 

—————— 

7This understanding of the Enabling Act has been the subject of substantial academic criticism, and rightfully so. See, e.g., Wright §4509,

at 264, 269–270, 272; Ely, The Irrepressible Myth of Erie, 87 Harv. 

L. Rev. 693, 719 (1974) (hereinafter Ely); see also R. Fallon, J. Manning, D. Meltzer, & D. Shapiro, Hart and Wechsler’s, The Federal 

Courts and the Federal System 593, n. 6 (6th ed. 2009) (discussing Ely). 8 JUSTICE SCALIA concedes as much, see ante, at 18–19, but argues 

that insofar as I allow for the possibility that a federal rule might

violate the Enabling Act when it displaces a seemingly procedural state 

rule, my approach is itself “unfaithful to the statute’s terms,” which 

cover “substantive rights” but not “procedural rules,” ante, at 19, n. 11 

(internal quotation marks omitted). This is not an objection to my

interpretation of the Enabling Act—that courts must look to whether a 

federal rule alters substantive rights in a given case—but simply to the 

way I would apply it, allowing for the possibility that a state rule that

regulates something traditionally considered to be procedural might

actually define a substantive right. JUSTICE SCALIA’s objection, moreover, misses the key point: In some instances, a state rule that appears

procedural really is not. A rule about how damages are reviewed on

appeal may really be a damages cap. See Gasperini, 518 U. S., at 427. 

A rule that a plaintiff can bring a claim for only three years may really

be a limit on the existence of the right to seek redress. A rule that a 

claim must be proved beyond a reasonable doubt may really be a 

definition of the scope of the claim. These are the sorts of rules that 
10 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

doing ignores the balance that Congress struck between

uniform rules of federal procedure and respect for a State’s 

construction of its own rights and remedies. It also ignores the separation-of-powers presumption, see Wright 

§4509, at 265, and federalism presumption, see Wyeth, 555 

U. S., at ___ (slip op., at 8), that counsel against judicially 

created rules displacing state substantive law.9 

—————— 

one might describe as “procedural,” but they nonetheless define substantive rights. Thus, if a federal rule displaced such a state rule, the 

federal rule would have altered the State’s “substantive rights.” 9 The plurality’s interpretation of the Enabling Act appears to mean 

that no matter how bound up a state provision is with the State’s own

rights or remedies, any contrary federal rule that happens to regulate 

“the manner and the means by which the litigants’ rights are enforced,” 

ante, at 13 (internal quotation marks omitted), must govern. There are 

many ways in which seemingly procedural rules may displace a State’s

formulation of its substantive law. For example, statutes of limitations,

although in some sense procedural rules, can also be understood as a

temporal limitation on legally created rights; if this Court were to 

promulgate a federal limitations period, federal courts would still, in

some instances, be required to apply state limitations periods. Similarly, if the federal rules altered the burden of proof in a case, this could 

eviscerate a critical aspect—albeit one that deals with how a right is 

enforced—of a State’s framework of rights and remedies. Or if a federal 

rule about appellate review displaced a state rule about how damages

are reviewed on appeal, the federal rule might be pre-empting a state

damages cap. Cf. Gasperini, 518 U. S., at 427. 

JUSTICE SCALIA responds that some of these federal rules might be

invalid under his view of the Enabling Act because they may not “really

regulat[e] procedure.” Ante, at 20, n. 13 (internal quotation marks 

omitted). This response, of course, highlights how empty the plurality’s

test really is. See n. 10, infra. The response is also limited to those 

rules that can be described as “regulat[ing]” substance, ante, at 13; it 

does not address those federal rules that alter the right at issue in the

litigation, see Sibbach v. Wilson & Co., 312 U. S. 1, 13–14 (1941), only

when they displace particular state laws. JUSTICE SCALIA speculates

that “Congress may well have accepted” the occasional alteration of 

substantive rights “as the price of a uniform system of federal procedure.” Ante, at 20–21, n. 13. Were we forced to speculate about the

balance that Congress struck, I might very well agree. But no speculation is necessary because Congress explicitly told us that federal rules 
Cite as: 559 U. S. ____ (2010) 11 

Opinion of STEVENS, J. 

Although the plurality appears to agree with much of

my interpretation of §2072, see ante, at 18–19, it nonetheless rejects that approach for two reasons, both of which 

are mistaken. First, JUSTICE SCALIA worries that if federal courts inquire into the effect of federal rules on state

law, it will enmesh federal courts in difficult determinations about whether application of a given rule would 

displace a state determination about substantive rights.

See ante, at 15, 21–22, and nn. 14, 15. I do not see why an 

Enabling Act inquiry that looks to state law necessarily is

more taxing than JUSTICE SCALIA’s.10 But in any event,

that inquiry is what the Enabling Act requires: While it 

may not be easy to decide what is actually a “substantive 

right,” “the designations substantive and procedural become important, for the Enabling Act has made them so.”

Ely 723; see also Wright §4509, at 266. The question,

therefore, is not what rule we think would be easiest on 

federal courts. The question is what rule Congress established. Although, JUSTICE SCALIA may generally prefer

easily administrable, bright-line rules, his preference does

not give us license to adopt a second-best interpretation of

the Rules Enabling Act. Courts cannot ignore text and 

—————— 

“shall not” alter “any” substantive right. §2072(b). 10 It will be rare that a federal rule that is facially valid under 28 

U. S. C. §2072 will displace a State’s definition of its own substantive 

rights. See Wright §4509, at 272 (observing that “unusual cases 

occasionally might arise in which . . . because of an unorthodox state 

rule of law, application of a Civil Rule . . . would intrude upon state 

substantive rights”). JUSTICE SCALIA’s interpretation, moreover, is not 

much more determinative than mine. Although it avoids courts’ having 

to evaluate state law, it tasks them with figuring out whether a federal

rule is really “procedural.” It is hard to know the answer to that 

question and especially hard to resolve it without considering the 

nature and functions of the state law that the federal rule will displace.

The plurality’s “ ‘test’ is no test at all—in a sense, it is little more than 

the statement that a matter is procedural if, by revelation, it is procedural.” Id., §4509, at 264. 
12 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

context in the service of simplicity.

Second, the plurality argues that its interpretation of 

the Enabling Act is dictated by this Court’s decision in 

Sibbach, which applied a Federal Rule about when parties

must submit to medical examinations. But the plurality 

misreads that opinion. As Justice Harlan observed in 

Hanna, “shorthand formulations which have appeared in

earlier opinions are prone to carry untoward results that

frequently arise from oversimplification.” 380 U. S., at 

475 (concurring opinion). To understand Sibbach, it is 

first necessary to understand the issue that was before the

Court. The petitioner raised only the facial question 

whether “Rules 35 and 37 [of the Federal Rules of Civil 

Procedure] are . . . within the mandate of Congress to this 

court” and not the specific question of “the obligation of

federal courts to apply the substantive law of a state.”11 

312 U. S., at 9. The Court, therefore, had no occasion to 

consider whether the particular application of the Federal 

Rules in question would offend the Enabling Act.12 

—————— 

11The petitioner in Sibbach argued only that federal rules could not

validly address subjects involving “important questions of policy,” Supp. 

Brief of Petitioner, O. T. 1940, No. 28, p. 7; see also Reply to Brief of 

Respondent, O. T. 1940, No. 28, p. 2 (summarizing that the petitioner

argued only that “[t]he right not to be compelled to submit to a physical

examination” is “a ‘substantive’ right forbidden by Congress” to be

addressed by the Federal Rules of Civil Procedure, “even though in 

theory the right is not of the character determinative of litigation”). In 

the petitioner’s own words, “[t]his contention. . . [did] not in itself

involve the [applicable] law of Illinois,” ibid., and the petitioner in her

briefing referenced the otherwise applicable state law only “to show 

that [she] was in a position to make the contention,” ibid., that is, to 

show that the federal court was applying a federal rule and not, under

the Rules of Decision Act, applying state law, see id., at 3. 12The plurality defends its view by including a long quote from two 

paragraphs of Sibbach. Ante, at 15–16. But the quoted passage of 

Sibbach describes only a facial inquiry into whether federal rules may 

“deal with” particular subject matter. 312 U. S., at 13. The plurality’s 

block quote, moreover, omits half of one of the quoted paragraphs, in 
Cite as: 559 U. S. ____ (2010) 13 

Opinion of STEVENS, J. 

 Nor, in Sibbach, was any further analysis necessary to

the resolution of the case because the matter at issue, 

requiring medical exams for litigants, did not pertain to

“substantive rights” under the Enabling Act. Although

most state rules bearing on the litigation process are 

adopted for some policy reason, few seemingly “procedural” rules define the scope of a substantive right or

remedy. The matter at issue in Sibbach reflected competing federal and state judgments about privacy interests.

Those privacy concerns may have been weighty and in

some sense substantive; but they did not pertain to the 

scope of any state right or remedy at issue in the litigation. Thus, in response to the petitioner’s argument in 

Sibbach that “substantive rights” include not only “rights

sought to be adjudicated by the litigants” but also “general 

principle[s]” or “question[s] of public policy that the legislature is able to pass upon,” id., at 2–3, we held that “the 

phrase ‘substantive rights’” embraces only state rights, 

such as the tort law in that case, that are sought to be

enforced in the judicial proceedings. Id., at 13–14. If the 

Federal Rule had in fact displaced a state rule that was

sufficiently intertwined with a state right or remedy, then 

perhaps the Enabling Act analysis would have been different.13 Our subsequent cases are not to the contrary.14 

—————— 

which the Court explained that the term “substantive rights” in the 

Enabling Act “certainly embraces such rights” as “rights conferred by

law to be protected and enforced,” such as “the right not to be injured in 

one’s person by another’s negligence” and “to redress [such] infraction.” 

Ibid. But whether a federal rule, for example, enlarges the right “to 

redress [an] infraction,” will depend on the state law that it displaces. 13Put another way, even if a federal rule in most cases “really regulates procedure,” Sibbach, 312 U. S., at 14, it does not “really regulat[e]

procedure” when it displaces those rare state rules that, although 

“procedural” in the ordinary sense of the term, operate to define the 

rights and remedies available in a case. This is so because what is 

procedural in one context may be substantive in another. See Hanna, 

380 U. S., at 471; Guaranty Trust Co. v. York, 326 U. S. 99, 108 (1945). 14Although this Court’s decision in Hanna cited Sibbach, that is of 
14 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

III 

JUSTICE GINSBURG views the basic issue in this case as 

whether and how to apply a federal rule that dictates an

answer to a traditionally procedural question (whether to

join plaintiffs together as a class), when a state law that

“defines the dimensions” of a state-created claim dictates 

the opposite answer. Post, at 12. As explained above, I

readily acknowledge that if a federal rule displaces a state 

rule that is “‘procedural’ in the ordinary sense of the 

term,” S. A. Healy Co., 60 F. 3d, at 310, but sufficiently 

interwoven with the scope of a substantive right or remedy, there would be an Enabling Act problem, and the

federal rule would have to give way. In my view, however, 

—————— 

little significance. Hanna did not hold that any seemingly procedural 

federal rule will always govern, even when it alters a substantive state 

right; nor, as in Sibbach, was the argument that I now make before the 

Court. Indeed, in Hanna we cited Sibbach’s statement that the Enabling Act prohibits federal rules that alter the rights to be adjudicated 

by the litigants, 312 U. S., at 13–14, for the proposition that “a court, in 

measuring a Federal Rule against the standards contained in the 

Enabling Act . . . need not wholly blind itself to the degree to which the 

Rule makes the character and result of the federal litigation stray from 

the course it would follow in state courts,” 380 U. S., at 473. And most 

of our subsequent decisions that have squarely addressed the framework for applying federal rules in diversity cases have not mentioned 

Sibbach at all but cited only Hanna. See, e.g., Burlington Northern R. 

Co. v. Woods, 480 U. S. 1, 5 (1987). 

JUSTICE SCALIA notes that in Mississippi Publishing Corp. v. 

Murphree, 326 U. S. 438 (1946), we used language that supported his 

view. See ante, at 13. But in that case, we contemplated only that the 

Federal Rule in question might have “incidental effects . . . upon the 

rights of litigants,” explaining that “[t]he fact that the application of 

Rule 4(f) will operate to subject petitioner’s rights to adjudication by

the district court for northern Mississippi” rather than southern Mississippi “will undoubtedly affect those rights.” 326 U. S., at 445–446. 

There was no suggestion that by affecting the method of enforcing the

rights in that case, the federal rules could plausibly abridge, enlarge, or

modify the rights themselves. 
Cite as: 559 U. S. ____ (2010) 15 

Opinion of STEVENS, J. 

this is not such a case. 

Rule 23 Controls Class Certification 

When the District Court in the case before us was asked 

to certify a class action, Federal Rule of Civil Procedure 23

squarely governed the determination whether the court 

should do so. That is the explicit function of Rule 23. Rule 

23, therefore, must apply unless its application would 

abridge, enlarge, or modify New York rights or remedies. 

Notwithstanding the plain language of Rule 23, I understand the dissent to find that Rule 23 does not govern the 

question of class certification in this matter because New 

York has made a substantive judgment that such a class 

should not be certified, as a means of proscribing damages. 

Although, as discussed infra, at 17–20, I do not accept the 

dissent’s view of §901(b), I also do not see how the dissent’s interpretation of Rule 23 follows from that view.15 I 

—————— 

15Nor do I see how it follows from the dissent’s premises that a class 

cannot be certified. The dissent contends that §901(b) is a damages 

“limitation,” post, at 7, n. 2, 8, 9, 12, 25, or “proscription,” post, at 12, 

n. 6, 21, whereas Rule 23 “does not command that a particular remedy

be available when a party sues in a representative capacity,” post, at 

11, and that consequently both provisions can apply. Yet even if the 

dissent’s premises were correct, Rule 23 would still control the question

whether petitioner may certify a class, and §901(b) would be relevant

only to determine whether petitioner, at the conclusion of a class-action

lawsuit, may collect statutory damages. 

It may be that if the dissent’s interpretation of §901(b) were correct, 

this class could not (or has not) alleged sufficient damages for the 

federal court to have jurisdiction, see 28 U. S. C. §1332(d)(6). But that 

issue was not raised in respondent’s motion to dismiss (from which the 

case comes to this Court), and it was not squarely presented to the 

Court. In any event, although the lead plaintiff has “acknowledged 

that its individual claim” is for less than the required amount in

controversy, see 549 F. 3d 137, 140 (CA2 2008), we do not know what

actual damages the entire class can allege. Thus, even if the Court 

were to adopt all of the dissent’s premises, I believe the correct disposition would be to vacate and remand for further consideration of 

whether the required amount in controversy has or can be met. 
16 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

agree with JUSTICE GINSBURG that courts should “avoi[d] 

immoderate interpretations of the Federal Rules that 

would trench on state prerogatives,” post, at 3–4, and 

should in some instances “interpre[t] the federal rules to 

avoid conflict with important state regulatory policies,” 

post, at 5 (internal quotation marks omitted). But that is 

not what the dissent has done. Simply because a rule 

should be read in light of federalism concerns, it does not 

follow that courts may rewrite the rule. 

At bottom, the dissent’s interpretation of Rule 23 seems 

to be that Rule 23 covers only those cases in which its 

application would create no Erie problem. The dissent 

would apply the Rules of Decision Act inquiry under Erie 

even to cases in which there is a governing federal rule, 

and thus the Act, by its own terms, does not apply. But 

“[w]hen a situation is covered by one of the Federal Rules, 

the question facing the court is a far cry from the typical, 

relatively unguided Erie choice.” Hanna, 380 U. S., at 

471. The question is only whether the Enabling Act is 

satisfied. Although it reflects a laudable concern to protect “state regulatory policies,” post, at 5 (internal quotation marks omitted), JUSTICE GINSBURG’s approach would, 

in my view, work an end run around Congress’ system of 

uniform federal rules, see 28 U. S. C. §2072, and our decision in Hanna. Federal courts can and should interpret 

federal rules with sensitivity to “state prerogatives,” post, 

at 4; but even when “state interests . . . warrant our respectful consideration,” post, at 8, federal courts cannot 

rewrite the rules. If my dissenting colleagues feel strongly 

that §901(b) is substantive and that class certification 

should be denied, then they should argue within the Enabling Act’s framework. Otherwise, “the Federal Rule 

applies regardless of contrary state law.” Gasperini, 518 

U. S., at 427, n. 7; accord, Hanna, 380 U. S., at 471. 
Cite as: 559 U. S. ____ (2010) 17 

Opinion of STEVENS, J. 

Applying Rule 23 Does Not Violate the Enabling Act 

As I have explained, in considering whether to certify a

class action such as this one, a federal court must inquire 

whether doing so would abridge, enlarge, or modify New 

York’s rights or remedies, and thereby violate the Enabling Act. This inquiry is not always a simple one because

“[i]t is difficult to conceive of any rule of procedure that

cannot have a significant effect on the outcome of a case,” 

Wright §4508, at 232–233, and almost “any rule can be 

said to have . . . ‘substantive effects,’ affecting society’s 

distribution of risks and rewards,” Ely 724, n. 170. Faced 

with a federal rule that dictates an answer to a traditionally procedural question and that displaces a state rule, 

one can often argue that the state rule was really some 

part of the State’s definition of its rights or remedies. 

In my view, however, the bar for finding an Enabling

Act problem is a high one. The mere fact that a state law 

is designed as a procedural rule suggests it reflects a

judgment about how state courts ought to operate and not

a judgment about the scope of state-created rights and 

remedies. And for the purposes of operating a federal

court system, there are costs involved in attempting to

discover the true nature of a state procedural rule and 

allowing such a rule to operate alongside a federal rule

that appears to govern the same question. The mere 

possibility that a federal rule would alter a state-created 

right is not sufficient. There must be little doubt. 

The text of CPLR §901(b) expressly and unambiguously 

applies not only to claims based on New York law but also

to claims based on federal law or the law of any other 

State. And there is no interpretation from New York

courts to the contrary. It is therefore hard to see how 

§901(b) could be understood as a rule that, though procedural in form, serves the function of defining New York’s 

rights or remedies. This is all the more apparent because 

lawsuits under New York law could be joined in federal 

class actions well before New York passed §901(b) in 1975, 
18 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

and New York had done nothing to prevent that. It is 

true, as the dissent points out, that there is a limited

amount of legislative history that can be read to suggest 

that the New York officials who supported §901(b) wished 

to create a “limitation” on New York’s “statutory damages.” Post, at 8. But, as JUSTICE SCALIA notes, that is 

not the law that New York adopted.16 See ante, at 7–8 

(opinion of the Court). 

The legislative history, moreover, does not clearly describe a judgment that §901(b) would operate as a limitation on New York’s statutory damages. In evaluating that 

—————— 

16 In its Erie analysis, the dissent observes that when sovereigns

create laws, the enacting legislatures sometimes assume those laws

will apply only within their territory. See post, at 18–20. That is a true 

fact, but it does not do very much work for the dissent’s position. For 

one thing, as the dissent observes, this Erie analysis is relevant only if 

there is no conflict between Rule 23 and §901(b), and the court can thus

apply both. Post, at 17. But because, in my view, Rule 23 applies, the 

only question is whether it would violate the Enabling Act. See Hanna, 

380 U. S., at 471. And that inquiry is different from the Rules of 

Decision Act, or Erie, inquiry. See id., at 469–471. 

The dissent’s citations, moreover, highlight simply that when interpreting statutes, context matters. Thus, we sometimes presume that

laws cover only domestic conduct and sometimes do not, depending 

upon, inter alia, whether it makes sense in a given situation to assume 

that “the character of an act as lawful or unlawful must be determined 

wholly by the law of the [place] where the act is done,” American 

Banana Co. v. United Fruit Co., 213 U. S. 347, 356 (1909). But in the 

context of §901(b), a presumption against extraterritoriality makes 

little sense. That presumption applies almost only to laws governing 

what people can or cannot do. Section 901(b), however, is not directed 

to the conduct of persons but is instead directed to New York courts.

Thus, §901(b) is, by its own terms, not extraterritorial insofar as it

states that it governs New York courts. It is possible that the New 

York Legislature simply did not realize that New York courts hear

claims under other sources of law and that other courts hear claims 

under New York law, and therefore mistakenly believed that they had

written a limit on New York remedies. But because New York set up

§901(b) as a general rule about how its courts operate, my strong

presumption is to the contrary. 
Cite as: 559 U. S. ____ (2010) 19 

Opinion of STEVENS, J. 

legislative history, it is necessary to distinguish between

procedural rules adopted for some policy reason and seemingly procedural rules that are intimately bound up in the 

scope of a substantive right or remedy. Although almost

every rule is adopted for some reason and has some effect 

on the outcome of litigation, not every state rule “defines

the dimensions of [a] claim itself,” post, at 12. New York 

clearly crafted §901(b) with the intent that only certain

lawsuits—those for which there were not statutory penalties—could be joined in class actions in New York courts. 

That decision reflects a policy judgment about which

lawsuits should proceed in New York courts in a class 

form and which should not. As JUSTICE GINSBURG carefully outlines, see post, at 8–10, §901(b) was “apparently” 

adopted in response to fears that the class-action procedure, applied to statutory penalties, would lead to “annihilating punishment of the defendant.” V. Alexander, Practice Commentaries, C901:11, reprinted in 7B McKinney’s

Consolidated Laws of New York Ann., p. 104 (2006) (internal quotation marks omitted); see also Sperry v. 

Crompton Corp., 8 N. Y. 3d 204, 211, 863 N. E. 2d 1012, 

1015 (2007). But statements such as these are not particularly strong evidence that §901(b) serves to define who 

can obtain a statutory penalty or that certifying such a

class would enlarge New York’s remedy. Any device that

makes litigation easier makes it easier for plaintiffs to

recover damages. 

In addition to the fear of excessive recoveries, some 

opponents of a broad class-action device “argued that there 

was no need to permit class actions in order to encourage 

litigation . . . when statutory penalties . . . provided an

aggrieved party with a sufficient economic incentive to 

pursue a claim.” Id., at 211, 863 N. E. 2d, at 1015 (emphasis added). But those opponents may have felt merely 

that, for any number of reasons, New York courts should 

not conduct trials in the class format when that format is 
20 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

unnecessary to motivate litigation.17 JUSTICE GINSBURG 

asserts that this could not be true because “suits seeking

statutory damages are arguably best suited to the class 

device because individual proof of actual damages is unnecessary.” Post, at 9–10. But some people believe that 

class actions are inefficient or at least unfair, insofar as 

they join together slightly disparate claims or force courts

to adjudicate unwieldy lawsuits. It is not for us to dismiss 

the possibility that New York legislators shared in those 

beliefs and thus wanted to exclude the class vehicle when 

it appeared to be unnecessary. 

The legislative history of §901 thus reveals a classically 

procedural calibration of making it easier to litigate claims

in New York courts (under any source of law) only when it 

is necessary to do so, and not making it too easy when the

class tool is not required. This is the same sort of calculation that might go into setting filing fees or deadlines for 

briefs. There is of course a difference of degree between

those examples and class certification, but not a difference 

of kind; the class vehicle may have a greater practical 

effect on who brings lawsuits than do low filing fees, but 

that does not transform it into a damages “proscription,” 

post, at 12, n. 6, 21, or “limitation,” post, at 7, n. 2, 8, 9, 12, 

25.18 

—————— 

17To be sure, one could imagine the converse story, that a legislature

would create statutory penalties but dictate that such penalties apply

only when necessary to overcome the costs and inconvenience of filing a

lawsuit, and thus are not necessary in a class action. But it is hard to 

see how that narrative applies to New York, given that New York’s

penalty provisions, on their face, apply to all plaintiffs, be they class or

individual, and that §901(b) addresses penalties that are created under

any source of state or federal law. 18 JUSTICE GINSBURG asserts that class certification in this matter 

would “transform a $500 case into a $5,000,000 award.” Post, at 1. But 

in fact, class certification would transform 10,000 $500 cases into one 

$5,000,000 case. It may be that without class certification, not all of

the potential plaintiffs would bring their cases. But that is true of any 
Cite as: 559 U. S. ____ (2010) 21 

Opinion of STEVENS, J. 

The difference of degree is relevant to the forum shopping considerations that are part of the Rules of Decision

Act or Erie inquiry. If the applicable federal rule did not 

govern the particular question at issue (or could be fairly

read not to do so), then those considerations would matter,

for precisely the reasons given by the dissent. See post, at 

17–24. But that is not this case. As the Court explained 

in Hanna, it is an “incorrect assumption that the rule of 

Erie R. Co. v. Thompkins constitutes the appropriate test 

of . . . the applicability of a Federal Rule of Civil Procedure.” 380 U. S., at 469–470. “It is true that both the 

Enabling Act and the Erie rule say, roughly, that federal

courts are to apply state ‘substantive’ law and federal

‘procedural’ law,” but the tests are different and reflect the

fact that “they were designed to control very different

sorts of decisions.” Id., at 471. 

Because Rule 23 governs class certification, the only

decision is whether certifying a class in this diversity case

would “abridge, enlarge or modify” New York’s substantive 

rights or remedies. §2072(b). Although one can argue

that class certification would enlarge New York’s “limited” 

damages remedy, see post, at 7, n. 2, 8, 9, 12, 25, such 

arguments rest on extensive speculation about what the 

New York Legislature had in mind when it created 

§901(b). But given that there are two plausible competing 

narratives, it seems obvious to me that we should respect 

the plain textual reading of §901(b), a rule in New York’s

procedural code about when to certify class actions 

brought under any source of law, and respect Congress’ 

decision that Rule 23 governs class certification in federal 

courts. In order to displace a federal rule, there must be 

more than just a possibility that the state rule is different 

—————— 

procedural vehicle; without a lower filing fee, a conveniently located

courthouse, easy-to-use federal procedural rules, or many other features of the federal courts, many plaintiffs would not sue. 
22 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

Opinion of STEVENS, J. 

than it appears. 

Accordingly, I concur in part and concur in the judgment. 
_________________ 

_________________ 

Cite as: 559 U. S. ____ (2010) 1 

GINSBURG, J., dissenting 

SUPREME COURT OF THE UNITED STATES 

No. 08–1008 

SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A., 

PETITIONER v. ALLSTATE INSURANCE 

COMPANY

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE SECOND CIRCUIT

[March 31, 2010] 

JUSTICE GINSBURG, with whom JUSTICE KENNEDY, 

JUSTICE BREYER, and JUSTICE ALITO join, dissenting. 

The Court today approves Shady Grove’s attempt to

transform a $500 case into a $5,000,000 award, although

the State creating the right to recover has proscribed this 

alchemy. If Shady Grove had filed suit in New York state 

court, the 2% interest payment authorized by New York

Ins. Law Ann. §5106(a) (West 2009) as a penalty for overdue benefits would, by Shady Grove’s own measure,

amount to no more than $500. By instead filing in federal

court based on the parties’ diverse citizenship and requesting class certification, Shady Grove hopes to recover, for

the class, statutory damages of more than $5,000,000.

The New York Legislature has barred this remedy, instructing that, unless specifically permitted, “an action to

recover a penalty, or minimum measure of recovery created or imposed by statute may not be maintained as a

class action.” N. Y. Civ. Prac. Law Ann. (CPLR) §901(b) 

(West 2006). The Court nevertheless holds that Federal 

Rule of Civil Procedure 23, which prescribes procedures

for the conduct of class actions in federal courts, preempts

the application of §901(b) in diversity suits. 

The Court reads Rule 23 relentlessly to override New 

York’s restriction on the availability of statutory damages. 
2 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

Our decisions, however, caution us to ask, before undermining state legislation: Is this conflict really necessary? 

Cf. Traynor, Is This Conflict Really Necessary? 37 Tex.

L. Rev. 657 (1959). Had the Court engaged in that inquiry, it would not have read Rule 23 to collide with New 

York’s legitimate interest in keeping certain monetary

awards reasonably bounded. I would continue to interpret 

Federal Rules with awareness of, and sensitivity to, important state regulatory policies. Because today’s judgment radically departs from that course, I dissent. 

I 

A 

 “Under the Erie doctrine,” it is long settled, “federal

courts sitting in diversity apply state substantive law and 

federal procedural law.” Gasperini v. Center for Humanities, Inc., 518 U. S. 415, 427 (1996); see Erie R. Co. v. 

Tompkins, 304 U. S. 64 (1938). Justice Harlan aptly

conveyed the importance of the doctrine; he described Erie 

as “one of the modern cornerstones of our federalism, 

expressing policies that profoundly touch the allocation of

judicial power between the state and federal systems.” 

Hanna v. Plumer, 380 U. S. 460, 474 (1965) (concurring 

opinion). Although we have found Erie’s application 

“sometimes [to be] a challenging endeavor,” Gasperini, 518 

U. S., at 427, two federal statutes mark our way. 

The first, the Rules of Decision Act,1 prohibits federal 

courts from generating substantive law in diversity actions. See Erie, 304 U. S., at 78. Originally enacted as

part of the Judiciary Act of 1789, this restraint serves a 

policy of prime importance to our federal system. We have 

—————— 

1The Rules of Decision Act directs that, “[t]he laws of the several 

states, except where the Constitution or treaties of the United States or

Acts of Congress otherwise require or provide, shall be regarded as 

rules of decision in civil actions in the courts of the United States, in 

cases where they apply.” 28 U. S. C. §1652. 
Cite as: 559 U. S. ____ (2010) 3 

GINSBURG, J., dissenting 

therefore applied the Act “with an eye alert to . . . avoiding 

disregard of State law.” Guaranty Trust Co. v. York, 326 

U. S. 99, 110 (1945).

The second, the Rules Enabling Act, enacted in 1934, 

authorizes us to “prescribe general rules of practice and

procedure” for the federal courts, but with a crucial restriction: “Such rules shall not abridge, enlarge or modify 

any substantive right.” 28 U. S. C. §2072. Pursuant to 

this statute, we have adopted the Federal Rules of Civil 

Procedure. In interpreting the scope of the Rules, including, in particular, Rule 23, we have been mindful of the

limits on our authority. See, e.g., Ortiz v. Fibreboard 

Corp., 527 U. S. 815, 845 (1999) (The Rules Enabling Act 

counsels against “adventurous application” of Rule 23; any 

tension with the Act “is best kept within tolerable limits.”); 

Amchem Products, Inc. v. Windsor, 521 U. S. 591, 612–613 

(1997). See also Semtek Int’l Inc. v. Lockheed Martin 

Corp., 531 U. S. 497, 503–504 (2001).

If a Federal Rule controls an issue and directly conflicts

with state law, the Rule, so long as it is consonant with 

the Rules Enabling Act, applies in diversity suits. See 

Hanna, 380 U. S., at 469–474. If, however, no Federal 

Rule or statute governs the issue, the Rules of Decision 

Act, as interpreted in Erie, controls. That Act directs 

federal courts, in diversity cases, to apply state law when

failure to do so would invite forum-shopping and yield 

markedly disparate litigation outcomes. See Gasperini, 

518 U. S., at 428; Hanna, 380 U. S., at 468. Recognizing

that the Rules of Decision Act and the Rules Enabling Act

simultaneously frame and inform the Erie analysis, we

have endeavored in diversity suits to remain safely within 

the bounds of both congressional directives. 

B 

In our prior decisions in point, many of them not mentioned in the Court’s opinion, we have avoided immoderate 
4 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

interpretations of the Federal Rules that would trench on

state prerogatives without serving any countervailing 

federal interest. “Application of the Hanna analysis,” we 

have said, “is premised on a ‘direct collision’ between the 

Federal Rule and the state law.” Walker v. Armco Steel 

Corp., 446 U. S. 740, 749–750 (1980) (quoting Hanna, 380 

U. S., at 472). To displace state law, a Federal Rule,

“when fairly construed,” must be “‘sufficiently broad’” so

as “to ‘control the issue’ before the court, thereby leaving 

no room for the operation of that law.” Burlington Northern R. Co. v. Woods, 480 U. S. 1, 4–5 (1987) (quoting 

Walker, 446 U. S., at 749–750, and n. 9; emphasis added); 

cf. Stewart Organization, Inc. v. Ricoh Corp., 487 U. S. 22, 

37–38 (1988) (SCALIA, J., dissenting) (“[I]n deciding

whether a federal . . . Rule of Procedure encompasses a 

particular issue, a broad reading that would create significant disuniformity between state and federal courts 

should be avoided if the text permits.”). 

 In pre-Hanna decisions, the Court vigilantly read the

Federal Rules to avoid conflict with state laws. In Palmer 

v. Hoffman, 318 U. S. 109, 117 (1943), for example, the 

Court read Federal Rule 8(c), which lists affirmative defenses, to control only the manner of pleading the listed 

defenses in diversity cases; as to the burden of proof in

such cases, Palmer held, state law controls. 

Six years later, in Ragan v. Merchants Transfer & 

Warehouse Co., 337 U. S. 530 (1949), the Court ruled that

state law determines when a diversity suit commences for 

purposes of tolling the state limitations period. Although

Federal Rule 3 specified that “[a] civil action is commenced 

by filing a complaint with the court,” we held that the

Rule did not displace a state law that tied an action’s 

commencement to service of the summons. Id., at 531– 

533. The “cause of action [wa]s created by local law,” the

Court explained, therefore “the measure of it [wa]s to be

found only in local law.” Id., at 533. 
Cite as: 559 U. S. ____ (2010) 5 

GINSBURG, J., dissenting 

 Similarly in Cohen v. Beneficial Industrial Loan Corp., 

337 U. S. 541 (1949), the Court held applicable in a diversity action a state statute requiring plaintiffs, as a prerequisite to pursuit of a stockholder’s derivative action, to 

post a bond as security for costs. At the time of the litigation, Rule 23, now Rule 23.1, addressed a plaintiff’s institution of a derivative action in federal court. Although the 

Federal Rule specified prerequisites to a stockholder’s

maintenance of a derivative action, the Court found no 

conflict between the Rule and the state statute in question; the requirements of both could be enforced, the Court 

observed. See id., at 556. Burdensome as the security-forcosts requirement may be, Cohen made plain, suitors 

could not escape the upfront outlay by resorting to the

federal court’s diversity jurisdiction. 

In all of these cases, the Court stated in Hanna, “the 

scope of the Federal Rule was not as broad as the losing 

party urged, and therefore, there being no Federal Rule 

which covered the point in dispute, Erie commanded the 

enforcement of state law.” 380 U. S., at 470. In Hanna 

itself, the Court found the clash “unavoidable,” ibid.; the 

petitioner had effected service of process as prescribed by 

Federal Rule 4(d)(1), but that “how-to” method did not 

satisfy the special Massachusetts law applicable to service 

on an executor or administrator. Even as it rejected the 

Massachusetts prescription in favor of the federal procedure, however, “[t]he majority in Hanna recognized . . . 

that federal rules . . . must be interpreted by the courts

applying them, and that the process of interpretation can 

and should reflect an awareness of legitimate state interests.” R. Fallon, J. Manning, D. Meltzer, & D. Shapiro,

Hart and Wechsler’s The Federal Courts and the Federal 

System 593 (6th ed. 2009) (hereinafter Hart & Wechsler). 

Following Hanna, we continued to “interpre[t] the federal rules to avoid conflict with important state regulatory 

policies.” Hart & Wechsler 593. In Walker, the Court took 
6 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

up the question whether Ragan should be overruled; we 

held, once again, that Federal Rule 3 does not directly

conflict with state rules governing the time when an action commences for purposes of tolling a limitations period. 446 U. S., at 749–752. Rule 3, we said, addresses 

only “the date from which various timing requirements of 

the Federal Rules begin to run,” id., at 751, and does not 

“purpor[t] to displace state tolling rules,” id., at 750–751. 

Significant state policy interests would be frustrated, we 

observed, were we to read Rule 3 as superseding the state

rule, which required actual service on the defendant to

stop the clock on the statute of limitations. Id., at 750– 

752. 

We were similarly attentive to a State’s regulatory 

policy in Gasperini. That diversity case concerned the

standard for determining when the large size of a jury

verdict warrants a new trial. Federal and state courts 

alike had generally employed a “shock the conscience” test

in reviewing jury awards for excessiveness. See 518 U. S., 

at 422. Federal courts did so pursuant to Federal Rule 

59(a) which, as worded at the time of Gasperini, instructed 

that a trial court could grant a new trial “for any of the

reasons for which new trials have heretofore been granted 

in actions at law in the courts of the United States.” Fed. 

Rule Civ. Proc. 59(a) (West 1995). In an effort to provide

greater control, New York prescribed procedures under 

which jury verdicts would be examined to determine

whether they “deviate[d] materially from what would be 

reasonable compensation.” See Gasperini, 518 U. S., at 

423–425 (quoting CPLR §5501(c)). This Court held that 

Rule 59(a) did not inhibit federal-court accommodation of 

New York’s invigorated test. 

Most recently, in Semtek, we addressed the claimpreclusive effect of a federal-court judgment dismissing a

diversity action on the basis of a California statute of 

limitations. The case came to us after the same plaintiff 
Cite as: 559 U. S. ____ (2010) 7 

GINSBURG, J., dissenting 

renewed the same fray against the same defendant in a 

Maryland state court. (Plaintiff chose Maryland because

that State’s limitations period had not yet run.) We held 

that Federal Rule 41(b), which provided that an involuntary dismissal “operate[d] as an adjudication on the merits,” did not bar maintenance of the renewed action in 

Maryland. To hold that Rule 41(b) precluded the Maryland courts from entertaining the case, we said, “would

arguably violate the jurisdictional limitation of the Rules 

Enabling Act,” 531 U. S., at 503, and “would in many cases 

violate [Erie’s] federalism principle,” id., at 504. 

In sum, both before and after Hanna, the abovedescribed decisions show, federal courts have been cautioned by this Court to “interpre[t] the Federal Rules . . .

with sensitivity to important state interests,” Gasperini, 

518 U. S., at 427, n. 7, and a will “to avoid conflict with 

important state regulatory policies,” id., at 438, n. 22 

(internal quotation marks omitted).2 The Court veers 

—————— 

2JUSTICE STEVENS stakes out common ground on this point: “[F]ederal

rules,” he observes, “must be interpreted with some degree of ‘sensitivity to important state interests and regulatory policies,’ . . . and applied

to diversity cases against the background of Congress’ command that

such rules not alter substantive rights and with consideration of ‘the

degree to which the Rule makes the character and result of the federal

litigation stray from the course it would follow in state courts,’ Hanna 

[v. Plumer], 380 U. S. [460, 473 (1965)].” Ante, at 3. (opinion concurring 

in part and concurring in judgment). See also ante, at 4 (“A ‘state

procedural rule, though undeniably procedural in the ordinary sense of 

the term’ may exist ‘to influence substantive outcomes,’ . . . and may in 

some instances become so bound up with the state-created right or

remedy that it defines the scope of that substantive right or remedy.”

(some internal quotation marks omitted)); ante, at 5 (“When a State

chooses to use a traditionally procedural vehicle as a means of defining

the scope of substantive rights or remedies, federal courts must recognize and respect that choice.”). Nevertheless, JUSTICE STEVENS sees no 

reason to read Rule 23 with restraint in this particular case; the Federal Rule preempts New York’s damages limitation, in his view, because §901(b) is “a procedural rule that is not part of New York’s 

substantive law.” Ante, at 1. This characterization of §901(b) does not 
8 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

away from that approach—and conspicuously, its most

recent reiteration in Gasperini, ante, at 11, n. 7—in favor 

of a mechanical reading of Federal Rules, insensitive to

state interests and productive of discord. 

C 

Our decisions instruct over and over again that, in the

adjudication of diversity cases, state interests—whether 

advanced in a statute, e.g., Cohen, or a procedural rule, 

e.g., Gasperini—warrant our respectful consideration. Yet 

today, the Court gives no quarter to New York’s limitation 

on statutory damages and requires the lower courts to 

thwart the regulatory policy at stake: To prevent excessive 

damages, New York’s law controls the penalty to which a

defendant may be exposed in a single suit. The story

behind §901(b)’s enactment deserves telling. 

In 1975, the Judicial Conference of the State of New 

York proposed a new class-action statute designed “to set 

up a flexible, functional scheme” that would provide “an

effective, but controlled group remedy.” Judicial Conference Report on CPLR, reprinted in 1975 N. Y. Laws

pp.1477, 1493 (McKinney). As originally drafted, the

legislation addressed only the procedural aspects of class

actions; it specified, for example, five prerequisites for 

certification, eventually codified at §901(a), that closely

tracked those listed in Rule 23. See CPLR §901(a) (requiring, for class certification, numerosity, predominance,

typicality, adequacy of representation, and superiority). 

While the Judicial Conference proposal was in the New 

York Legislature’s hopper, “various groups advocated for 

the addition of a provision that would prohibit class action 

plaintiffs from being awarded a statutorily-created penalty 

—————— 

mirror reality, as I later explain. See infra, at 17–24. But a majority of

this Court, it bears emphasis, agrees that Federal Rules should be read 

with moderation in diversity suits to accommodate important state 

concerns. 
Cite as: 559 U. S. ____ (2010) 9 

GINSBURG, J., dissenting 

. . . except when expressly authorized in the pertinent 

statute.” Sperry v. Crompton Corp., 8 N. Y. 3d 204, 211, 

863 N. E. 2d 1012, 1015 (2007). These constituents 

“feared that recoveries beyond actual damages could lead 

to excessively harsh results.” Ibid. “They also argued that

there was no need to permit class actions . . . [because] 

statutory penalties . . . provided an aggrieved party with a

sufficient economic incentive to pursue a claim.” Ibid. 

Such penalties, constituents observed, often far exceed a

plaintiff’s actual damages. “When lumped together,” they 

argued, “penalties and class actions produce overkill.” 

Attachment to Letter from G. Perkinson, New York State 

Council of Retail Merchants, Inc., to J. Gribetz, Executive 

Chamber (June 4, 1975) (Legislative Report), Bill Jacket, 

L. 1975, Ch. 207. 

Aiming to avoid “annihilating punishment of the defendant,” the New York Legislature amended the proposed 

statute to bar the recovery of statutory damages in class 

actions. V. Alexander, Practice Commentaries, C901:11, 

reprinted in 7B McKinney’s Consolidated Laws of New 

York Ann., p. 104 (2006) (internal quotation marks omitted). In his signing statement, Governor Hugh Carey

stated that the new statute “empowers the court to prevent abuse of the class action device and provides a controlled remedy.” Memorandum on Approving L. 1975, Ch. 

207, reprinted in 1975 N. Y. Laws, at 1748 (emphasis

added).

“[T]he final bill . . . was the result of a compromise 

among competing interests.” Sperry, 8 N. Y. 3d, at 211, 

863 N. E. 2d, at 1015. Section 901(a) allows courts leeway

in deciding whether to certify a class, but §901(b) rejects 

the use of the class mechanism to pursue the particular 

remedy of statutory damages. The limitation was not 

designed with the fair conduct or efficiency of litigation in 

mind. Indeed, suits seeking statutory damages are arguably best suited to the class device because individual proof 
10 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

of actual damages is unnecessary. New York’s decision 

instead to block class-action proceedings for statutory 

damages therefore makes scant sense, except as a means 

to a manifestly substantive end: Limiting a defendant’s

liability in a single lawsuit in order to prevent the exorbitant inflation of penalties—remedies the New York Legislature created with individual suits in mind.3 

D 

Shady Grove contends—and the Court today agrees—

that Rule 23 unavoidably preempts New York’s prohibition on the recovery of statutory damages in class actions.

The Federal Rule, the Court emphasizes, states that 

Shady Grove’s suit “may be” maintained as a class action,

which conflicts with §901(b)’s instruction that it “may not” 

so proceed. Ante, at 4 (internal quotation marks omitted 

and emphasis deleted). Accordingly, the Court insists,

§901(b) “cannot apply in diversity suits unless Rule 23 is

ultra vires.” Ibid. Concluding that Rule 23 does not violate the Rules Enabling Act, the Court holds that the

federal provision controls Shady Grove’s ability to seek, on

behalf of a class, a statutory penalty of over $5,000,000. 

Ante, at 12–16 (plurality opinion); ante, at 17–22 (STEVENS, 

J., concurring in part and concurring in judgment). 

The Court, I am convinced, finds conflict where none is 

—————— 

3 Even in the mine-run case, a class action can result in “potentially 

ruinous liability.” Advisory Committee’s Notes on Fed. Rule Civ. 

Proc. 23, 28 U. S. C. App., p. 143. A court’s decision to certify a class 

accordingly places pressure on the defendant to settle even unmeritorious claims. See, e.g., Coopers & Lybrand v. Livesay, 437 U. S. 463, 476 

(1978). When representative plaintiffs seek statutory damages, pressure to settle may be heightened because a class action poses the risk of

massive liability unmoored to actual injury. See, e.g., Ratner v. Chemical Bank New York Trust Co., 54 F. R. D. 412, 416 (SDNY 1972) (exercising “considerable discretion of a pragmatic nature” to refuse to 

certify a class because the plaintiffs suffered negligible actual damages

but sought statutory damages of $13,000,000). 
Cite as: 559 U. S. ____ (2010) 11 

GINSBURG, J., dissenting 

necessary. Mindful of the history behind §901(b)’s enactment, the thrust of our precedent, and the substantiverights limitation in the Rules Enabling Act, I conclude, as

did the Second Circuit and every District Court to have

considered the question in any detail,4 that Rule 23 does 

not collide with §901(b). As the Second Circuit well understood, Rule 23 prescribes the considerations relevant to 

class certification and postcertification proceedings—but it

does not command that a particular remedy be available 

when a party sues in a representative capacity. See 549 

F. 3d 137, 143 (2008).5 Section 901(b), in contrast, trains 

on that latter issue. Sensibly read, Rule 23 governs procedural aspects of class litigation, but allows state law to

control the size of a monetary award a class plaintiff may 

pursue. 

—————— 

4See, e.g., In re Automotive Refinishing Paint Antitrust Litigation, 

515 F. Supp. 2d 544, 549–551 (ED Pa. 2007); Leider v. Ralfe, 387 F. 

Supp. 2d 283, 289–292 (SDNY 2005); Dornberger v. Metropolitan Life 

Insurance Co., 182 F. R. D. 72, 84 (SDNY 1999). See also Weber v. U. S. 

Sterling Securities, Inc., 282 Conn. 722, 738–739, 914 A. 2d 816, 827– 

828 (2007) (section 901(b) applied in Connecticut state court to action

governed by New York substantive law). 5Shady Grove projects that a dispensation in favor of Allstate would 

require “courts in all diversity class actions . . . [to] look to state rules 

and decisional law rather than to Rule 23 . . . in making their class 

certification decisions.” Brief for Petitioner 55. This slippery-slope 

projection is both familiar and false. Cf. R. Bork, The Tempting of 

America 169 (1990) (“Judges and lawyers live on the slippery slope of

analogies; they are not supposed to ski it to the bottom.”). In this case, 

CPLR §901(a) lists the state-law prerequisites for class certification,

but Allstate does not contend that §901(a) overrides Rule 23. Brief for 

Respondent 18 (“There is no dispute that the criteria for class certification under state law do not apply in federal court; that is the ground 

squarely occupied by Rule 23.”). Federal courts sitting in diversity have

routinely applied Rule 23’s certification standards, rather than comparable state provisions. See, e.g., In re New Motor Vehicles Canadian 

Export Antitrust Litigation, 522 F. 3d 6, 18–24 (CA1 2008); Order and 

Reasons in In re Katrina Canal Breaches Consolidated Litigation, Civ. 

Action No. 05–4182 (ED La., Aug. 6, 2009). 
12 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

In other words, Rule 23 describes a method of enforcing

a claim for relief, while §901(b) defines the dimensions of 

the claim itself. In this regard, it is immaterial that 

§901(b) bars statutory penalties in wholesale, rather than

retail, fashion. The New York Legislature could have

embedded the limitation in every provision creating a 

cause of action for which a penalty is authorized; §901(b) 

operates as shorthand to the same effect. It is as much a 

part of the delineation of the claim for relief as it would be 

were it included claim by claim in the New York Code.

The Court single-mindedly focuses on whether a suit 

“may” or “may not” be maintained as a class action. See 

ante, at 4–6. Putting the question that way, the Court 

does not home in on the reason why. Rule 23 authorizes 

class treatment for suits satisfying its prerequisites because the class mechanism generally affords a fair and 

efficient way to aggregate claims for adjudication. Section 

901(b) responds to an entirely different concern; it does

not allow class members to recover statutory damages

because the New York Legislature considered the result of 

adjudicating such claims en masse to be exorbitant.6 The 

fair and efficient conduct of class litigation is the legitimate concern of Rule 23; the remedy for an infraction of 

state law, however, is the legitimate concern of the State’s 

lawmakers and not of the federal rulemakers. Cf. Ely, The 

Irrepressible Myth of Erie, 87 Harv. L. Rev. 693, 722 

(1974) (It is relevant “whether the state provision embodies a substantive policy or represents only a procedural 

disagreement with the federal rulemakers respecting the 

—————— 

6The Court disputes the strength of the evidence of legislative intent, 

see ante, at 9, but offers no alternative account of §901(b)’s purpose. 

Perhaps this silence indicates how very hard it would be to ascribe to

§901(b) any purpose bound up with the fairness and efficiency of

processing cases. On its face, the proscription is concerned with remedies, i.e., the availability of statutory damages in a lawsuit. Legislative 

history confirms this objective, but is not essential to revealing it. 
Cite as: 559 U. S. ____ (2010) 13 

GINSBURG, J., dissenting 

fairest and most efficient way of conducting litigation.”). 

Suppose, for example, that a State, wishing to cap damages in class actions at $1,000,000, enacted a statute

providing that “a suit to recover more than $1,000,000 

may not be maintained as a class action.” Under the 

Court’s reasoning—which attributes dispositive significance to the words “may not be maintained”—Rule 23 

would preempt this provision, nevermind that Congress,

by authorizing the promulgation of rules of procedure for 

federal courts, surely did not intend to displace statecreated ceilings on damages.7 The Court suggests that the 

analysis might differ if the statute “limit[ed] the remedies 

available in an existing class action,” ante, at 7, such that 

Rule 23 might not conflict with a state statute prescribing

that “no more than $1,000,000 may be recovered in a class 

action.” There is no real difference in the purpose and 

intended effect of these two hypothetical statutes. The 

notion that one directly impinges on Rule 23’s domain, 

while the other does not, fundamentally misperceives the

office of Rule 23.8 

—————— 

7There is, of course, a difference between “justly administering [a] 

remedy,” Sibbach v. Wilson & Co., 312 U. S. 1, 14 (1941), and prescribing the content of that remedy; if Rule 23 can be read to increase a 

plaintiff’s recovery from $1,000,000 to some greater amount, the Rule

has arguably “enlarge[d] . . . [a] substantive right” in violation of the 

Rules Enabling Act. 28 U. S. C. §2072(b). The plurality appears to

acknowledge this point, stating that the Federal Rules we have found 

to be in compliance with the Act have not “altered . . . available remedies.” Ante, at 13. But the Court’s relentless reading of Rule 23 today

does exactly that: The Federal Rule, it says, authorizes the recovery of

class-size statutory damages even though the New York provision 

instructs that such penalties shall not be available. 8The Court states that “[w]e cannot rewrite [a state law] to reflect 

our perception of legislative purpose.” Ante, at 9. But we can, of 

course, interpret the Federal Rules in light of a State’s regulatory policy

to decide whether and to what extent a Rule preempts state law. See 

supra, at 3–7. Just as we read Federal Rule 3 in Walker v. Armco Steel 

Corp., 446 U. S. 740, 751 (1980), not to govern when a suit commences 
14 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

The absence of an inevitable collision between Rule 23 

and §901(b) becomes evident once it is comprehended that 

a federal court sitting in diversity can accord due respect

to both state and federal prescriptions. Plaintiffs seeking 

to vindicate claims for which the State has provided a

statutory penalty may pursue relief through a class action

if they forgo statutory damages and instead seek actual 

damages or injunctive or declaratory relief; any putative

class member who objects can opt out and pursue actual 

damages, if available, and the statutory penalty in an

individual action. See, e.g., Mendez v. The Radec Corp., 

260 F. R. D. 38, 55 (WDNY 2009); Brzychnalski v. Unesco, 

Inc., 35 F. Supp. 2d 351, 353 (SDNY 1999).9 See also 

Alexander, Practice Commentaries, at 105 (“Even if a

statutory penalty or minimum recovery is involved, most

courts hold that it can be waived, thus confining the class 

recovery to actual damages and eliminating the bar of 

CPLR 901(b).”). In this manner, the Second Circuit ex-

—————— 

for purposes of tolling a state statute of limitations (although the Rule

indisputably controls when an action commences for federal procedural

purposes), so too we could read Rule 23 not to direct when a class action 

may be maintained for purposes of recovering statutory damages 

prescribed by state law. On this reading of Rule 23, no rewriting of

§901(b) is necessary to avoid a conflict. 9The New York Legislature appears to have anticipated this result.

In discussing the remedial bar effected by §901(b), the bill’s sponsor 

explained that a “statutory class action for actual damages would still

be permissible.” S. Fink, [Sponsor’s] Memorandum, Bill Jacket, L. 

1975, Ch. 207. See also State Consumer Protection Board Memorandum (May 29, 1975), Bill Jacket, L. 1975, Ch. 207. On this understanding, New York courts routinely authorize class actions when the class 

waives its right to receive statutory penalties. See, e.g., Cox v. Microsoft Corp., 8 App. Div. 3d 39, 778 N. Y. S. 2d 147 (2004); Pesantez v. 

Boyle Env. Servs., Inc., 251 App. Div. 2d 11, 673 N. Y. S. 2d 659 (1998); 

Ridge Meadows Homeowners’ Assn., Inc. v. Tara Development Co., 242 

App. Div. 2d 947, 665 N. Y. S. 2d 361 (1997); Super Glue Corp. v. Avis 

Rent A Car System, Inc., 132 App. Div. 2d 604, 517 N. Y. S. 2d 764 

(1987); Weinberg v. Hertz Corp., 116 App. Div. 2d 1, 499 N. Y. S. 2d 693 

(1986). 
Cite as: 559 U. S. ____ (2010) 15 

GINSBURG, J., dissenting 

plained, “Rule 23’s procedural requirements for class

actions can be applied along with the substantive requirement of CPLR 901(b).” 549 F. 3d, at 144. In sum, 

while phrased as responsive to the question whether

certain class actions may begin, §901(b) is unmistakably 

aimed at controlling how those actions must end. On that 

remedial issue, Rule 23 is silent. 

Any doubt whether Rule 23 leaves §901(b) in control of 

the remedial issue at the core of this case should be dispelled by our Erie jurisprudence, including Hanna, which 

counsels us to read Federal Rules moderately and cautions

against stretching a rule to cover every situation it could

conceivably reach.10 The Court states that “[t]here is no 

reason . . . to read Rule 23 as addressing only whether 

claims made eligible for class treatment by some other law 

should be certified as class actions.” Ante, at 5. To the 

contrary, Palmer, Ragan, Cohen, Walker, Gasperini, and 

Semtek provide good reason to look to the law that creates 

the right to recover. See supra, at 4–7. That is plainly so 

on a more accurate statement of what is at stake: Is there 

any reason to read Rule 23 as authorizing a claim for relief

when the State that created the remedy disallows its

pursuit on behalf of a class? None at all is the answer our 

federal system should give. 

Notably, New York is not alone in its effort to contain

penalties and minimum recoveries by disallowing class 

relief; Congress, too, has precluded class treatment for

certain claims seeking a statutorily designated minimum 

recovery. See, e.g., 15 U. S. C. §1640(a)(2)(B) (Truth in

Lending Act) (“[I]n the case of a class action . . . no mini-

—————— 

10The plurality notes that “we have rejected every statutory challenge to a Federal Rule that has come before us.” Ante, at 13. But it 

omits that we have interpreted Rules with due restraint, including Rule 

23, thus diminishing prospects for the success of such challenges. See 

Ortiz v. Fibreboard Corp., 527 U. S. 815, 842 (1999); Amchem Products, 

Inc. v. Windsor, 521 U. S. 591, 612–613 (1997); supra, at 4–8. 
16 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

mum recovery shall be applicable.”); §1693m(a)(2)(B) 

(Electronic Fund Transfer Act) (same); 12 U. S. C. 

§4010(a)(2)(B)(i) (Expedited Fund Availability Act) (same).

Today’s judgment denies to the States the full power 

Congress has to keep certain monetary awards within

reasonable bounds. Cf. Beard v. Kindler, 558 U. S. ___, 

___ (2009) (slip op., at 8) (“In light of . . . federalism and 

comity concerns . . . it would seem particularly strange to

disregard state . . . rules that are substantially similar to 

those to which we give full force in our own courts.”). 

States may hesitate to create determinate statutory penalties in the future if they are impotent to prevent federalcourt distortion of the remedy they have shaped.11 

By finding a conflict without considering whether Rule

23 rationally should be read to avoid any collision, the 

Court unwisely and unnecessarily retreats from the federalism principles undergirding Erie. Had the Court reflected on the respect for state regulatory interests endorsed in our decisions, it would have found no cause to 

interpret Rule 23 so woodenly—and every reason not to do 

so. Cf. Traynor, 37 Tex. L. Rev., at 669 (“It is bad enough 

for courts to prattle unintelligibly about choice of law, but 

—————— 

11States have adopted a variety of formulations to limit the use of

class actions to gain certain remedies or to pursue certain claims, as

illustrated by the 96 examples listed in Allstate’s brief. Apps. to Brief 

for Respondent. The Court’s “one-size-fits-all” reading of Rule 23, ante, 

at 4, likely prevents the enforcement of all of these statutes in diversity

actions—including the numerous state statutory provisions that, like

§901(b), attempt to curb the recovery of statutory damages. See, e.g.,

Cal. Civ. Code Ann. §2988.5(a)(2) (West 1993); Colo. Rev. Stat. Ann.

§12–14.5–235(d) (2009); Conn. Gen. Stat. §36a–683(a) (2009); Haw.

Rev. Stat. §489–7.5(b)(1) (2008); Ind. Code §24–4.5–5–203(a)(2) (2004);

Ky. Rev. Stat. Ann. §367.983(1)(c) (West 2006); Mass. Gen. Laws, ch. 

167B, §20(a)(2)(B) (2008); Mich. Comp. Laws Ann. §493.112(3)(c) (West

2005); N. M. Stat. Ann. §58–16–15(B) (Lexis 2004); Ohio Rev. Code 

Ann. §1351.08(A) (West 2004); Okla. Stat., Tit. 14A, §5–203(1) (2007

Supp.); Wyo. Stat. Ann. §40–19–119(a)(iii) (2009). 
Cite as: 559 U. S. ____ (2010) 17 

GINSBURG, J., dissenting 

unforgiveable when inquiry might have revealed that 

there was no real conflict.”). 

II 

Because I perceive no unavoidable conflict between Rule

23 and §901(b), I would decide this case by inquiring

“whether application of the [state] rule would have so 

important an effect upon the fortunes of one or both of the 

litigants that failure to [apply] it would be likely to cause a 

plaintiff to choose the federal court.” Hanna, 380 U. S., at 

468, n. 9. See Gasperini, 518 U. S., at 428. 

Seeking to pretermit that inquiry, Shady Grove urges

that the class-action bar in §901(b) must be regarded as

“procedural” because it is contained in the CPLR, which 

“govern[s] the procedure in civil judicial proceedings in all 

courts of the state.” Brief for Petitioner 34 (quoting CPLR

§101; emphasis in original). Placement in the CPLR is 

hardly dispositive. The provision held “substantive” for 

Erie purposes in Gasperini is also contained in the CPLR 

(§5501(c)), as are limitations periods, §201 et seq., prescriptions plainly “substantive” for Erie purposes however 

they may be characterized for other purposes, see York, 

326 U. S., at 109–112. See also, e.g., 1 Restatement (Second) of Conflict of Laws §133, Reporter’s Note, p. 369 

(1969) (hereinafter Restatement) (“Under the rule of Erie 

. . . the federal courts have classified the burden of persuasion as to contributory negligence as a matter of substantive law that is governed by the rule of the State in which 

they sit even though the courts of that State have characterized their rule as procedural for choice-of-law purposes.”); Cook, “Substance” and “Procedure” in the Conflict

of Laws, 42 Yale L. J. 333 (1933). 

Shady Grove also ranks §901(b) as “procedural” because 

“nothing in [the statute] suggests that it is limited to 

rights of action based on New York state law, as opposed 

to federal law or the law of other states”; instead it “ap-
18 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

plies to actions seeking penalties under any statute.” Brief 

for Petitioner 35–36. See also ante, at 17–18 (STEVENS, J., 

concurring in part and concurring in judgment) (Section

901(b) cannot “be understood as a rule that . . . serves the

function of defining New York’s rights or remedies” because

its “text . . . expressly and unambiguously applies not only

to claims based on New York law but also to claims based on 

federal law or the law of any other State.”). 

It is true that §901(b) is not specifically limited to claims 

arising under New York law. But neither is it expressly 

extended to claims arising under foreign law. The rule 

prescribes, without elaboration either way, that “an action

to recover a penalty . . . may not be maintained as a class 

action.” We have often recognized that “general words” 

appearing in a statute may, in fact, have limited application; “[t]he words ‘any person or persons,’” for example, 

“are broad enough to comprehend every human being.

But general words must not only be limited to cases within 

the jurisdiction of the state, but also to those objects to 

which the legislature intended to apply them.” United 

States v. Palmer, 3 Wheat. 610, 631 (1818) (opinion for the 

Court by Marshall, C. J.). See also Small v. United States, 

544 U. S. 385, 388 (2005) (“In law, a legislature that uses

the statutory phrase ‘any person’ may or may not mean to 

include ‘persons’ outside the jurisdiction of the state.” 

(some internal quotation marks omitted)); Flora v. United 

States, 362 U. S. 145, 149 (1960) (The term “‘any sum’ is a

catchall [phrase,] . . . but to say this is not to define what

it catches.”).

Moreover, Shady Grove overlooks the most likely explanation for the absence of limiting language: New York 

legislators make law with New York plaintiffs and defendants in mind, i.e., as if New York were the universe. See 

Baxter, Choice of Law and the Federal System, 16 Stan. 

L. Rev. 1, 11 (1963) (“[L]awmakers often speak in universal terms but must be understood to speak with reference 
Cite as: 559 U. S. ____ (2010) 19 

GINSBURG, J., dissenting 

to their constituents.”); cf. Smith v. United States, 507 

U. S. 197, 204, n. 5 (1993) (presumption against extraterritoriality rooted in part in “the commonsense notion that

Congress generally legislates with domestic concerns in

mind”).

The point was well put by Brainerd Currie in his seminal article on governmental interest analysis in conflict-oflaws cases. The article centers on a now-archaic Massachusetts law that prevented married women from binding 

themselves by contract as sureties for their husbands. 

Discussing whether the Massachusetts prescription applied to transactions involving foreign factors (a foreign

forum, foreign place of contracting, or foreign parties), 

Currie observed: 

“When the Massachusetts legislature addresses itself

to the problem of married women as sureties, the undeveloped image in its mind is that of Massachusetts 

married women, husbands, creditors, transactions, 

courts, and judgments. In the history of AngloAmerican law the domestic case has been normal, the 

conflict-of-laws case marginal.” Married Women’s 

Contracts: A Study in Conflict-of-Laws Method, 25 U.

Chi. L. Rev. 227, 231 (1958) (emphasis added). 

Shady Grove’s suggestion that States must specifically 

limit their laws to domestic rights of action if they wish

their enactments to apply in federal diversity litigation 

misses the obvious point: State legislators generally do not 

focus on an interstate setting when drafting statutes.12 

—————— 

12Shady Grove’s argument that §901(b) is procedural based on its 

possible application to foreign claims is also out of sync with our Erie 

decisions, many of them involving state statutes of similarly unqualified scope. The New Jersey law at issue in Cohen v. Beneficial Industrial Loan Corp., 337 U. S. 541, 544, n. 1 (1949), for example, required

plaintiffs to post a bond as security for costs in “any [stockholder’s

derivative] action.” (quoting 1945 N. J. Laws ch. 131 (emphasis 
20 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

Shady Grove also observes that a New York court has

applied §901(b) to a federal claim for relief under the 

Telephone Consumer Protection Act of 1991 (TCPA), 47 

U. S. C. §227, see Rudgayzer & Gratt v. Cape Canaveral 

Tour & Travel, Inc., 22 App. Div. 3d 148, 799 N. Y. S. 2d 

795 (2005), thus revealing §901(b)’s “procedural” cast. 

Brief for Petitioner 36. We note first that the TCPA itself 

calls for the application of state law. See Rudgayzer, 22 

App. Div. 3d, at 149–150, 799 N. Y. S. 2d, at 796–797 

(federal action authorized in state court “if otherwise 

permitted by the laws or rules of the court of [the] State”

(quoting 47 U. S. C. §227(b)(3))). See also Gottlieb v. 

Carnival Corp., 436 F. 3d 335, 342 (CA2 2006) (Sotomayor,

J.) (“Congress sought, via the TCPA, to enact the functional equivalent of a state law.”). The TCPA, the Supreme Court of Connecticut has recognized, thus “carves 

out an exception to th[e] general rule” that “when Erie . . . 

is reversed . . . , a state court hearing a federal case is

normally required to apply federal substantive law”: “Under §227(b)(3) . . . it is state substantive law that determines, as a preliminary matter, whether a federal action 

under the act may be brought in state court.” Weber v. 

U. S. Sterling Securities, Inc., 282 Conn. 722, 736, 924 

A. 2d 816, 826 (2007) (in TCPA action governed by New 

York substantive law, §901(b) applied even though the 

claim was pursued in Connecticut state court). 

—————— 

added)). See also, e.g., Walker, 446 U. S., at 742–743, and n. 4 (Oklahoma statute deemed “[a]n action” commenced for purposes of the

statute of limitations upon service of the summons (quoting Okla. Stat.,

Tit. 12, §97 (1971)). Our characterization of a state statute as substantive for Erie purposes has never hinged on whether the law applied only

to domestic causes of action. To the contrary, we have ranked as

substantive a variety of state laws that the state courts apply to federal

and out-of-state claims, including statutes of limitations and burden-ofproof prescriptions. See infra, at 21. 
Cite as: 559 U. S. ____ (2010) 21 

GINSBURG, J., dissenting 

Moreover, statutes qualify as “substantive” for Erie 

purposes even when they have “procedural” thrusts as 

well. See, e.g., Cohen, 337 U. S., at 555; cf. Woods v. Interstate Realty Co., 337 U. S. 535, 536–538, and n. 1 (1949)

(holding diversity case must be dismissed based on state

statute that, by its terms, governed only proceedings in 

state court). Statutes of limitations are, again, exemplary. 

They supply “substantive” law in diversity suits, see York, 

326 U. S., at 109–112, even though, as Shady Grove acknowledges, state courts often apply the forum’s limitations period as a “procedural” bar to claims arising under 

the law of another State, see Reply Brief 24, n. 16; Tr. of

Oral Arg. 16–17. See also Restatement §§142–143 (when 

adjudicating a foreign cause of action, State may use 

either its own or the foreign jurisdiction’s statute of limitations, whichever is shorter). Similarly, federal courts

sitting in diversity give effect to state laws governing the 

burden of proving contributory negligence, see Palmer v. 

Hoffman, 318 U. S. 109, 177 (1943), yet state courts adjudicating foreign causes of action often apply their own

local law to this issue. See Restatement §133 and Reporter’s Note. 

In short, Shady Grove’s effort to characterize §901(b) as 

simply “procedural” cannot successfully elide this fundamental norm: When no federal law or rule is dispositive of 

an issue, and a state statute is outcome affective in the 

sense our cases on Erie (pre- and post-Hanna) develop, the

Rules of Decision Act commands application of the State’s

law in diversity suits. Gasperini, 518 U. S., at 428; 

Hanna, 380 U. S., at 468, n. 9; York, 326 U. S., at 109. As 

this case starkly demonstrates, if federal courts exercising 

diversity jurisdiction are compelled by Rule 23 to award

statutory penalties in class actions while New York courts 

are bound by §901(b)’s proscription, “substantial variations between state and federal [money judgments] may be

expected.” Gasperini, 518 U. S., at 430 (quoting Hanna, 
22 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

380 U. S., at 467–468 (internal quotation marks omitted)). 

The “variation” here is indeed “substantial.” Shady Grove

seeks class relief that is ten thousand times greater than

the individual remedy available to it in state court. As the 

plurality acknowledges, ante, at 22, forum shopping will 

undoubtedly result if a plaintiff need only file in federal 

instead of state court to seek a massive monetary award 

explicitly barred by state law. See Gasperini, 518 U. S., at 

431 (“Erie precludes a recovery in federal court significantly larger than the recovery that would have been

tolerated in state court.”).13 The “accident of diversity of

citizenship,” Klaxon Co. v. Stentor Elec. Mfg. Co., 313 U. S. 

487, 496 (1941), should not subject a defendant to such

augmented liability. See Hanna, 380 U. S., at 467 (“The 

Erie rule is rooted in part in a realization that it would be 

unfair for the character or result of a litigation materially

to differ because the suit had been brought in a federal 

court.”).

It is beyond debate that “a statutory cap on damages

would supply substantive law for Erie purposes.” 

Gasperini, 518 U. S., at 428. See also id., at 439–440 

(STEVENS, J., dissenting) (“A state-law ceiling on allowable 

damages . . . is a substantive rule of decision that federal

courts must apply in diversity cases governed by New

York law.”); id., at 464 (SCALIA, J., dissenting) (“State 

substantive law controls what injuries are compensable

and in what amount.”). In Gasperini, we determined that 

New York’s standard for measuring the alleged excessive-

—————— 

13 In contrast, many “state rules ostensibly addressed to procedure,” 

ante, at 10 (majority opinion)—including pleading standards and rules

governing summary judgment, pretrial discovery, and the admissibility

of certain evidence—would not so hugely impact forum choices. It is 

difficult to imagine a scenario that would promote more forum shopping

than one in which the difference between filing in state and federal

court is the difference between a potential award of $500 and one of

$5,000,000. 
Cite as: 559 U. S. ____ (2010) 23 

GINSBURG, J., dissenting 

ness of a jury verdict was designed to provide a control

analogous to a damages cap. Id., at 429. The statute was 

framed as “a procedural instruction,” we noted, “but the

State’s objective [wa]s manifestly substantive.” Ibid. 

Gasperini’s observations apply with full force in this 

case. By barring the recovery of statutory damages in a

class action, §901(b) controls a defendant’s maximum

liability in a suit seeking such a remedy. The remedial 

provision could have been written as an explicit cap: “In 

any class action seeking statutory damages, relief is limited to the amount the named plaintiff would have recovered in an individual suit.” That New York’s Legislature 

used other words to express the very same meaning 

should be inconsequential. 

We have long recognized the impropriety of displacing, 

in a diversity action, state-law limitations on state-created

remedies. See Woods, 337 U. S., at 538 (in a diversity 

case, a plaintiff “barred from recovery in the state court

. . . should likewise be barred in the federal court”); York, 

326 U. S., at 108–109 (federal court sitting in diversity

“cannot afford recovery if the right to recover is made

unavailable by the State nor can it substantively affect the

enforcement of the right as given by the State”). Just as 

Erie precludes a federal court from entering a deficiency 

judgment when a State has “authoritatively announced

that [such] judgments cannot be secured within its borders,” Angel v. Bullington, 330 U. S. 183, 191 (1947), so too 

Erie should prevent a federal court from awarding statutory penalties aggregated through a class action when 

New York prohibits this recovery. See also Ragan, 337 

U. S., at 533 (“Where local law qualifies or abridges [a 

claim], the federal court must follow suit. Otherwise there 

is a different measure of the cause of action in one court 

than in the other, and the principle of Erie . . . is transgressed.”). In sum, because “New York substantive law 

governs [this] claim for relief, New York law . . . guide[s] 
24 SHADY GROVE ORTHOPEDIC ASSOCIATES, P. A. 

v. ALLSTATE INS. CO. 

GINSBURG, J., dissenting 

the allowable damages.” Gasperini, 518 U. S., at 437.14 

III 

The Court’s erosion of Erie’s federalism grounding impels me to point out the large irony in today’s judgment.

Shady Grove is able to pursue its claim in federal court 

only by virtue of the recent enactment of the Class Action 

Fairness Act of 2005 (CAFA), 28 U. S. C. §1332(d). In 

CAFA, Congress opened federal-court doors to state-lawbased class actions so long as there is minimal diversity, 

at least 100 class members, and at least $5,000,000 in 

controversy. Ibid. By providing a federal forum, Congress

sought to check what it considered to be the overreadiness 

of some state courts to certify class actions. See, e.g.,

S. Rep. No. 109–14, p. 4 (2005) (CAFA prevents lawyers 

from “gam[ing] the procedural rules [to] keep nationwide 

or multi-state class actions in state courts whose judges

have reputations for readily certifying classes.” (internal

quotation marks omitted)); id., at 22 (disapproving “the ‘I 

never met a class action I didn’t like’ approach to class

certification” that “is prevalent in state courts in some

localities”). In other words, Congress envisioned fewer—

not more—class actions overall. Congress surely never

anticipated that CAFA would make federal courts a mecca 

for suits of the kind Shady Grove has launched: class

actions seeking state-created penalties for claims arising 

under state law—claims that would be barred from class 

treatment in the State’s own courts. Cf. Woods, 337 U. S., 

at 537 (“[T]he policy of Erie . . . preclude[s] maintenance in 

—————— 

14There is no question that federal courts can “give effect to the substantive thrust of [§901(b)] without untoward alteration of the federal

scheme for the trial and decision of civil cases.” Gasperini, 518 U. S., at 

426. There is no risk that individual plaintiffs seeking statutory

penalties will flood federal courts with state-law claims that could be

managed more efficiently on a class basis; the diversity statute’s 

amount-in-controversy requirement ensures that small state-law 

disputes remain in state court. 
Cite as: 559 U. S. ____ (2010) 25 

GINSBURG, J., dissenting 

. . . federal court . . . of suits to which the State ha[s] closed 

its courts.”).15 

* * * 

I would continue to approach Erie questions in a manner mindful of the purposes underlying the Rules of Decision Act and the Rules Enabling Act, faithful to precedent, 

and respectful of important state interests. I would therefore hold that the New York Legislature’s limitation on the 

recovery of statutory damages applies in this case, and 

would affirm the Second Circuit’s judgment. 

—————— 

15 It remains open to Congress, of course, to exclude from federalcourt jurisdiction under the Class Action Fairness Act of 2005, 28 

U. S. C. §1332(d), claims that could not be maintained as a class action

in state court.