Royal Canin U. S. A. v. Wullschleger

(Slip Opinion) OCTOBER TERM, 2024 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

ROYAL CANIN U. S. A., INC., ET AL. v.

WULLSCHLEGER ET AL.

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR

THE EIGHTH CIRCUIT

No. 23–677. Argued October 7, 2024—Decided January 15, 2025

Respondent Anastasia Wullschleger sued petitioner Royal Canin

U. S. A., Inc., in state court, alleging that Royal Canin had engaged in

deceptive marketing practices. Her original complaint asserted claims

based on both federal and state law. Royal Canin removed the case to

federal court under 28 U. S. C. §1441(a). That removal was premised

on Wullschleger’s federal claim, which gave rise to federal-question ju-

risdiction and also allowed the federal court to exercise supplemental

jurisdiction over Wullschleger’s factually intertwined state claims.

§§1331, 1367. But federal court is not where Wullschleger wanted the

case to be resolved. So she amended her complaint, deleting every

mention of federal law, and petitioned the District Court for a remand

to state court. The District Court denied Wullschleger’s request, but

the Eighth Circuit reversed. In the Eighth Circuit’s view, Wull-

schleger’s amendment had eliminated any basis for federal-question

jurisdiction. And without a federal question, the court concluded,

there was no possibility of supplemental jurisdiction over Wull-

schleger’s state-law claims.

Held: When a plaintiff amends her complaint to delete the federal-law

claims that enabled removal to federal court, leaving only state-law

claims behind, the federal court loses supplemental jurisdiction over

the state claims, and the case must be remanded to state court. Pp. 6–

20.

(a) Under the text of §1367, the supplemental-jurisdiction statute, a

post-removal amendment to a complaint that eliminates any basis for

federal-question jurisdiction also divests a federal court of supple-

mental jurisdiction over remaining state-law claims. Subsection (a)

states that “in any civil action of which the district courts have original

2 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Syllabus

jurisdiction, the district courts shall have supplemental jurisdiction

over all other claims that are so related to claims in the action within

such original jurisdiction that they form part of the same case or con-

troversy.” The statute thus confers supplemental jurisdiction over

state-law claims sharing a sufficient factual relationship with the fed-

eral claims in a case. And in Rockwell Int’l Corp. v. United States, 549

U. S. 457, 473–474, this Court held that “when a plaintiff files a com-

plaint in federal court and then voluntarily amends the complaint,

courts look to the amended complaint to determine jurisdiction.” So

under §1367(a), when the plaintiff in an original case amends her com-

plaint to withdraw the federal claims, leaving only state claims behind,

she divests the federal court of supplemental jurisdiction. And the re-

sult must be the same in a removed case, because nothing in §1367(a)’s

text distinguishes between cases removed to federal court and cases

originally filed there.

The exclusion from §1367(a) of such post-amendment state-law

claims is reflected in the text of §1367(c). Subsection (c) provides that

a district court “may decline to exercise supplemental jurisdiction”

over state-law claims covered by §1367(a)’s jurisdictional grant in

three specific situations where the state-law claims overshadow the

federal claims in a case. If §1367(a)’s grant of jurisdiction included the

leftover state claims in an amended complaint, they too would have

appeared on §1367(c)’s list: Even more than the claims addressed

there, they are ill-suited to federal adjudication. That §1367(c) makes

no mention of such claims demonstrates that §1367(a) does not extend

to them.

That result accords with Congress’s usual view of how amended

pleadings can affect jurisdiction. On that view, apparent in varied fed-

eral statutes, an amendment can wipe the jurisdictional slate clean,

giving rise to a new analysis with a different conclusion. E.g., §1653

(“[d]efective allegations of jurisdiction may be amended” so a case can

come within a federal court’s jurisdiction); §1446(b)(3) (even “if the

case stated by the initial pleading is not removable,” the defendant can

remove the case after receiving “an amended pleading” establishing a

basis for federal jurisdiction); §1332(d)(7) (similar). And just the same

here: Section 1367 contemplates that when an amended complaint is

filed, the jurisdictional basis for the suit is reviewed anew. Pp. 7–10.

(b) That reading of §1367 also parallels a slew of other procedural

rules linking jurisdiction to the amended, rather than initial, com-

plaint. In deciding which substantive claims to bring against which

defendants, a plaintiff can establish—or not—the basis for a federal

court’s subject-matter jurisdiction. And her control over those matters

extends beyond the time her first complaint is filed. If a plaintiff

amends her complaint, the new pleading supersedes the old one and

Cite as: 604 U. S. ____ (2025) 3

Syllabus

can bring the suit either newly within or newly outside a federal court’s

jurisdiction. Thus, as Rockwell explained, if “a plaintiff files a com-

plaint in federal court and later voluntarily amends the complaint” to

“withdraw[ ]” the allegations supporting federal jurisdiction, that

amendment “will defeat jurisdiction” unless the withdrawn allegations

were “replaced by others” giving the court adjudicatory power. 549

U. S., at 473–474.

Rockwell’s rule has a host of variations in both original and removed

federal cases. Adding federal claims can create original jurisdiction

where it once was wanting. See, e.g., ConnectU LLC v. Zuckerberg,

522 F. 3d 82, 91. And an amendment can either destroy or create ju-

risdiction in an original diversity case. See Owen Equipment & Erec-

tion Co. v. Kroger, 437 U. S. 365, 374–377; Newman-Green, Inc. v. Al-

fonzo-Larrain, 490 U. S. 826, 832–833. Similarly, if removing a case

was improper because the initial complaint did not contain a federal

claim, the plaintiff’s later assertion of such a claim establishes juris-

diction going forward. See Pegram v. Herdrich, 530 U. S. 211, 215–

216, and n. 2. And by the same token, amending a complaint in a re-

moved case to join a non-diverse party destroys diversity jurisdiction,

and the federal court must remand the case to state court. See

§1447(e). In removed and original cases alike, the rule that jurisdic-

tion follows the operative pleading ensures that the case, as it will ac-

tually be litigated, merits a federal forum. Pp. 10–15.

(c) Royal Canin contends that this Court has twice before reached

the opposite conclusion—first, in Carnegie-Mellon Univ. v. Cohill, 484

U. S. 343, and next in Rockwell, in a footnote. But in each case, the

relied-on passage is extraneous to the Court’s holding and reasoning,

and so cannot bear the weight of Royal Canin’s argument. The footnote

in Rockwell does state the rule Royal Canin propounds: “[W]hen a de-

fendant removes a case to federal court based on the presence of a fed-

eral claim,” it says, “an amendment eliminating the original basis for

federal jurisdiction generally does not defeat jurisdiction.” 549 U. S.,

at 474, n. 6. But Rockwell was an original federal case, not a removed

one, so its drive-by assertion of a jurisdictional rule for removed cases

was entirely outside the issue being decided. That dictum cannot over-

come the Court’s analysis here or Rockwell’s own core insight that fed-

eral courts “look to the amended complaint to determine jurisdiction.”

Id., at 474. Pp. 15–20.

75 F. 4th 918, affirmed.

KAGAN, J., delivered the opinion for a unanimous Court.

Cite as: 604 U. S. ____ (2025) 1

Opinion of the Court

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

United States Reports. Readers are requested to notify the Reporter of

Decisions, Supreme Court of the United States, Washington, D. C. 20543,

pio@supremecourt.gov, of any typographical or other formal errors.

SUPREME COURT OF THE UNITED STATES

_________________

No. 23–677

_________________

ROYAL CANIN U. S. A., INC., ET AL., PETITIONERS v.

ANASTASIA WULLSCHLEGER, ET AL.

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE EIGHTH CIRCUIT

[January 15, 2025]

JUSTICE KAGAN delivered the opinion of the Court.

If a complaint filed in state court asserts federal-law

claims, the defendant may remove the case to federal court.

See 28 U. S. C. §1441(a). And if the complaint also asserts

state-law claims arising out of the same facts, the federal

court may adjudicate those claims too, in the exercise of

what is called supplemental jurisdiction. See §1367.

This case presents a further question: What happens if,

after removal, the plaintiff amends her complaint to delete

all the federal-law claims, leaving nothing but state-law

claims behind? May the federal court still adjudicate the

now purely state-law suit? We hold that it may not. When

an amendment excises the federal-law claims that enabled

removal, the federal court loses its supplemental jurisdic-

tion over the related state-law claims. The case must there-

fore return to state court.

I

A

“Federal courts,” we have often explained, “are courts of

limited jurisdiction.” E.g., Kokkonen v. Guardian Life Ins.

Co. of America, 511 U. S. 375, 377 (1994). Limited first by

2 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

the Constitution, to only the kinds of “Cases” and “Contro-

versies” listed in Article III. And for all lower federal

courts, limited as well by statute. Congress determines,

through its grants of jurisdiction, which suits those courts

can resolve. So, for example, Congress has always given

federal courts power to decide “diversity” cases, between

“citizens of different States” whose dispute involves more

than a stated sum (the so-called amount-in-controversy).

§1332(a). And of special importance here, Congress has

long conferred jurisdiction on federal courts to resolve cases

“arising under” federal law. §1331.

“Arising under” jurisdiction—more often known as fed-

eral-question jurisdiction—enables federal courts to decide

cases founded on federal law. A suit most typically falls

within that statutory grant “when federal law creates the

cause of action asserted.” Gunn v. Minton, 568 U. S. 251,

257 (2013). On rare occasions, the grant also covers a suit

containing state-law claims alone, because one or more of

them “necessarily raise[s]” a “substantial” and “actually

disputed” federal question. Id., at 258. Either way, the de-

termination of jurisdiction is based only on the allegations

in the plaintiff ’s “well-pleaded complaint”—not on any is-

sue the defendant may raise. Franchise Tax Bd. of Cal. v.

Construction Laborers Vacation Trust for Southern Cal.,

463 U. S. 1, 9–10 (1983). That longstanding rule makes the

complaint—the plaintiff ’s own claims and allegations—the

key to “arising under” jurisdiction. If the complaint pre-

sents no federal question, a federal court may not hear the

suit.

But if a complaint includes the requisite federal question,

a federal court often has power to decide state-law ques-

tions too. Suppose a complaint with two claims—one based

on federal, the other on state, law. This Court held in Mine

Workers v. Gibbs, 383 U. S. 715, 725 (1966), that a federal

court may exercise supplemental jurisdiction over the state

Cite as: 604 U. S. ____ (2025) 3

Opinion of the Court

claim so long as it “derive[s] from” the same “nucleus of op-

erative fact” as the federal one. The Gibbs Court reasoned

that when the two claims are so closely related, they make

up “but one constitutional ‘case’ ”; and the Court presumed

that Congress wanted in that situation to confer jurisdic-

tion up to the Constitution’s limit. Ibid. (quoting U. S.

Const., Art. III, §2, cl. 1); see Exxon Mobil Corp. v. Allapat-

tah Services, Inc., 545 U. S. 546, 553 (2005). Congress later

confirmed that view, generally codifying Gibbs’s supple-

mental-jurisdiction rule in 28 U. S. C. §1367 (whose text we

will soon consider, see infra, at 7–8). Under that statute,

as under Gibbs, jurisdiction over a federal-law claim brings

with it supplemental jurisdiction over a state-law claim

arising from the same facts. That derivative jurisdiction,

though, is to some extent discretionary; §1367 spells out cir-

cumstances, again derived from Gibbs, in which a federal

court may decline to hear a state claim falling within the

statute’s bounds. See §1367(c); Gibbs, 383 U. S., at 726–

727.

And yet one more preparatory point: If a statute confers

federal jurisdiction over a suit, not only the plaintiff but

also the defendant can get it into federal court. Take the

“arising under” statute: It grants federal district courts

“original jurisdiction” over cases presenting a federal ques-

tion. §1331; see §1332 (similarly providing “original juris-

diction” over diversity suits). The plaintiff may avail her-

self of that jurisdiction (and of the opportunity §1367

affords to add supplemental state claims); but she also may

file her suit in state court. If she takes the latter route,

another statute then gives the defendant an option. Be-

cause the case falls within the federal courts’ “original ju-

risdiction,” the defendant may “remove[ ]” it from state to

federal court. §1441(a). And there the case (including sup-

plemental state claims) usually remains. Except that “[i]f

at any time before final judgment it appears that the dis-

trict court lacks subject matter jurisdiction,” the case must

4 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

be “remanded” to state court. §1447(c). That is because, to

return to where we started, federal courts are courts of lim-

ited jurisdiction: When they do not have (or no longer have)

authorization to resolve a suit, they must hand it over.

B

Before raising issues demanding a jurisdictional primer,

this case was all about the marketing of dog food. Petitioner

Royal Canin U. S. A., Inc., manufactures a brand of dog

food available only with a veterinarian’s prescription—and

thus sold at a premium price. Respondent Anastasia Wull-

schleger purchased the food, thinking it contained medica-

tion not found in off-the-shelf products. She later learned

it did not. Her suit, initially filed in a Missouri state court,

contends that Royal Canin’s dog food is ordinary dog food:

The company sells the product with a prescription not be-

cause its ingredients make that necessary, but solely to fool

consumers into paying a jacked-up price. Her original com-

plaint asserted claims under the Missouri Merchandising

Practices Act and state antitrust law. It also alleged viola-

tions of the Federal Food, Drug, and Cosmetic Act (FDCA),

21 U. S. C. §301 et seq.

And so began the procedural back-and-forth that eventu-

ally landed Wullschleger’s case in this Court. Royal Canin

went first: It removed the case to federal court based on the

asserted violations of the FDCA. 1 That removal properly

——————

1 That first step provoked an earlier jurisdictional battle, resolved in

favor of allowing removal and not at issue here. The dispute arose be-

cause Wullschleger’s complaint alleged the FDCA violations not as inde-

pendent federal claims, but instead in support of her state claims. Did

the complaint, then, contain the needed federal question? The Court of

Appeals held that it did because the meaning of the referenced FDCA

provisions was thoroughly embedded in, and integral to the success of,

Wullschleger’s state-law claims. See Wullschleger v. Royal Canin

U. S. A., Inc., 953 F. 3d 519, 522 (CA8 2020) (citing Gunn v. Minton, 568

U. S. 251, 258 (2013)); see supra, at 2. We here treat that finding of fed-

eral-question jurisdiction as a given. And for ease of exposition, we take

Cite as: 604 U. S. ____ (2025) 5

Opinion of the Court

brought to the District Court not only Wullschleger’s FDCA

claims, but also her factually intertwined state-law claims.

The parties were thus set to litigate the entire suit in fed-

eral court. But that is not where Wullschleger wanted the

case to be resolved. So she countered Royal Canin’s move:

She amended her complaint to delete its every mention of

the FDCA, leaving her state claims to stand on their own.

And with that amended, all-state-law complaint in hand,

she petitioned the District Court to remand the case to state

court.

Although the District Court denied Wullschleger’s re-

quest, the Court of Appeals for the Eighth Circuit reversed

that decision and ordered a remand. See 75 F. 4th 918, 924

(2023). 2 In the Eighth Circuit’s view, Wullschleger’s

amendment had eliminated any basis for federal jurisdic-

tion. An amended complaint, the court reasoned, “[super-

sedes] an original complaint and renders the original com-

plaint without legal effect.” Id., at 922 (alteration in

original). And nothing in the amended complaint supported

federal-question jurisdiction: It was, after all, now based

entirely on state law. Nor could the District Court now ex-

ercise supplemental jurisdiction over Wullschleger’s state-

law claims. “[T]he possibility of supplemental jurisdiction,”

the court reasoned, “vanished right alongside the once-

present federal questions.” Id., at 924. And that analysis

held good even though it was Royal Canin, rather than

Wullschleger, that had brought the suit to the District

Court: “It makes no difference,” the Eighth Circuit stated,

that the case “end[ed] up in federal court through removal.”

Id., at 922.

——————

a slight liberty throughout this opinion, referring to the original com-

plaint’s FDCA allegations simply as federal claims.

2 Because the denial of a remand request is not immediately appeala-

ble, see Caterpillar Inc. v. Lewis, 519 U. S. 61, 74 (1996), the issue

reached the Court of Appeals only after the District Court dismissed

Wullschleger’s amended complaint on the merits.

6 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

Other Courts of Appeals have reached the opposite con-

clusion, holding that a post-removal amendment cannot di-

vest a federal court of jurisdiction. 3 On that view, “[t]he

existence of subject matter jurisdiction is determined by ex-

amining the complaint as it existed at the time of removal.”

Harper v. AutoAlliance Int’l, Inc., 392 F. 3d 195, 210 (CA6

2004). So the District Court here would have retained sup-

plemental jurisdiction over Wullschleger’s state-law claims

even after she amended her complaint to delete all her

federal-law ones.

We granted certiorari to resolve the Circuit split, 601

U. S. ___ (2024), and we now affirm the decision below.

II

When a plaintiff amends her complaint following her

suit’s removal, a federal court’s jurisdiction depends on

what the new complaint says. If (as here) the plaintiff elim-

inates the federal-law claims that enabled removal, leaving

only state-law claims behind, the court’s power to decide the

dispute dissolves. With the loss of federal-question juris-

diction, the court loses as well its supplemental jurisdiction

over the state claims. That conclusion fits the text of §1367,

governing supplemental jurisdiction. And it accords with a

bevy of rules hinging federal jurisdiction on the allegations

made in an amended complaint, because that complaint has

become the operative one. Royal Canin argues that our

precedent makes an exception for when an amendment fol-

lows a lawsuit’s removal, but that is to read two bits of gra-

tuitous language for a good deal more than they are worth.

——————

3 Ching v. Mitre Corp., 921 F. 2d 11, 13 (CA1 1990); Collura v. Phila-

delphia, 590 Fed. Appx. 180, 184 (CA3 2014) (per curiam); Harless v. CSX

Hotels, Inc., 389 F. 3d 444, 448 (CA4 2004); Harper v. AutoAlliance Int’l,

Inc., 392 F. 3d 195, 210–211 (CA6 2004); Behlen v. Merrill Lynch, 311 F.

3d 1087, 1095 (CA11 2002).

Cite as: 604 U. S. ____ (2025) 7

Opinion of the Court

A

Begin with §1367, entitled “Supplemental jurisdiction.”

Subsection (a) states the basic rule:

“Except as provided in subsections (b) and (c) or as ex-

pressly provided otherwise by Federal statute, in any

civil action of which the district courts have original ju-

risdiction, the district courts shall have supplemental

jurisdiction over all other claims that are so related to

claims in the action within such original jurisdiction

that they form part of the same case or controversy un-

der Article III of the United States Constitution.”

The subsection thus takes as its starting point claims

within a federal district court’s original jurisdiction—be-

cause, say, they turn on federal law. See §1331. It then

confers authority on the court to decide certain “other”

claims in the same suit, involving only state law. That

added authority—the court’s supplemental jurisdiction—

extends to claims “so related to” the claims supporting orig-

inal jurisdiction as to form “part of the same [constitutional]

case.” And that needed relationship, Gibbs explains, is one

of fact: The federal court has supplemental jurisdiction over

state-law claims sharing a “common nucleus of operative

fact” with the federal-law ones. 383 U. S., at 725; see supra,

at 2–3.

Skip down a bit and subsection (c) explains that the sup-

plemental jurisdiction just conferred is in some measure

discretionary. That subsection provides that a district

court “may decline to exercise supplemental jurisdiction” in

three specific situations: (1) if the supplemental claim

“raises a novel or complex issue of State law”; (2) if the sup-

plemental claim “substantially predominates” over the

claims within the court’s original jurisdiction; and (3) if the

district court “has dismissed all claims over which it has

8 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

original jurisdiction.” 4 In all those contexts, federal law is

not where the real action is. So although supplemental ju-

risdiction persists, the district court need not exercise it: In-

stead, the court may (and indeed, ordinarily should) kick

the case to state court. See Gibbs, 383 U. S., at 726–727.

In addressing the text of §1367, Royal Canin argues pri-

marily from the first subsection’s grant of jurisdiction. The

language there is “broad,” the company says: Section

1367(a) grants “supplemental jurisdiction over ‘all other

claims’ within the case or controversy, unless Congress ‘ex-

pressly provided otherwise.’ ” Reply Brief 2 (emphasis in

original). And Congress did not expressly provide that an

amendment deleting federal claims eliminates supple-

mental jurisdiction. See id., at 4–5. The upshot, Royal

Canin says, is the rule it espouses: The amendment of a

complaint following removal of a suit to federal court cannot

divest that court of supplemental jurisdiction.

But that position founders on an undisputed point: Noth-

ing in §1367’s text—including in the text Royal Canin high-

lights—distinguishes between cases removed to federal

court and cases originally filed there. See Tr. of Oral Arg.

7–8. Whatever that text says about removed cases, it also

says about original ones, and vice versa. That means if (as

Royal Canin urges) §1367(a)’s language prevents an

amendment from ousting supplemental jurisdiction in re-

moved cases, then so too it does in original ones. But here

is the rub: In original cases, this Court has already reached

the opposite conclusion. The pertinent rule comes from

Rockwell Int’l Corp. v. United States, 549 U. S. 457, 473–

474 (2007): “[W]hen a plaintiff files a complaint in federal

court and then voluntarily amends the complaint, courts

look to the amended complaint to determine jurisdiction.”

——————

4 A fourth, more general provision, which neither party thinks relevant

here, allows a court to decline supplemental jurisdiction “in exceptional

circumstances,” for “other compelling reasons.” 28 U. S. C. §1367(c)(4).

Cite as: 604 U. S. ____ (2025) 9

Opinion of the Court

So when the plaintiff in an original case amends her com-

plaint to withdraw the federal claims, leaving only state

claims behind, she divests the federal court of adjudicatory

power. See ibid. Royal Canin concedes that result, as it

must. See Tr. of Oral Arg. 6–7. The position it adopts—

applying only in removed cases—is indeed designed not to

collide with Rockwell’s ruling. But once §1367(a) is taken

as consistent with Rockwell, it cannot say what the com-

pany posits. Under that provision—as under Rockwell—an

amendment excising all federal claims divests a court of

supplemental jurisdiction over the remaining state claims

in an original case. And if in an original case, then also in

a removed case—because, again, §1367(a) draws no distinc-

tion between the two.

The exclusion from §1367(a) of such post-amendment

state-law claims is reflected in the text of §1367(c). Recall

that §1367(c) describes three contexts in which state-law

claims, though covered by §1367(a)’s jurisdictional grant,

are often better given to state courts. See supra, at 7–8. If

§1367(a)’s grant included the leftover state claims in an

amended complaint, they too would have appeared on

§1367(c)’s list: Even more than the claims addressed there,

they are ill-suited to federal adjudication. The leftover

state claims, after all, are now the entirety of the plaintiff ’s

suit. Federal claims are not just subordinate, as in

§§1367(c)(1) and (2), but gone. And gone for good as well.

When federal claims are dismissed by the district court, as

in §1367(c)(3), an appellate court may yet revive them; but

that cannot happen when the plaintiff has excised them

through a proper amendment. So, again, it follows: If

§1367(a) conferred supplemental jurisdiction over the

claims here, §1367(c) would make that jurisdiction discre-

tionary. That §1367(c) does not do so—that even while it

addresses, for example, dismissals of federal claims, it

makes no mention of amendments deleting them—shows

that §1367(a) does not extend so far. Or otherwise said,

10 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

there is no discretion to decline supplemental jurisdiction

here because there is no supplemental jurisdiction at all.

Once the plaintiff has ditched all claims involving federal

questions, the leftover state claims are supplemental to

nothing—and §1367(a) does not authorize a federal court to

resolve them.

That result accords with Congress’s usual view of how

amended pleadings can affect jurisdiction. On that view,

apparent in varied federal statutes, an amendment can

wipe the jurisdictional slate clean, giving rise to a new anal-

ysis with a different conclusion. Consider 28 U. S. C. §1653:

It states broadly that, in both trial and appellate courts,

“[d]efective allegations of jurisdiction may be amended” to

ensure that a case can go forward. So a case falling outside

the federal court’s jurisdiction can come within it by virtue

of an amendment. Or take the statute laying out proce-

dures for removal. It provides that even “if the case stated

by the initial pleading is not removable,” an amendment

may make it so: The defendant can remove the case after

receiving “an amended pleading” establishing that the case

is newly subject to federal jurisdiction. §1446(b)(3); see

§1332(d)(7) (similarly providing that an “amended com-

plaint” in a proposed class action may create “[f]ederal ju-

risdiction”). In such statutes, Congress conceives of amend-

ments as having the potential to alter jurisdiction. And just

the same here. Section 1367 contemplates that when an

amended complaint is filed, the jurisdictional basis for the

suit is reviewed anew. If nothing in the amended complaint

now falls “within [the federal court’s] original jurisdiction,”

then neither does anything fall within the court’s “supple-

mental jurisdiction.” §1367(a). In the superseding plead-

ing, the state-law claims are just state-law claims, outside

§1367(a)’s purview.

B

That reading of §1367 also parallels a slew of other,

Cite as: 604 U. S. ____ (2025) 11

Opinion of the Court

mainly judge-made procedural rules linking jurisdiction to

the amended, rather than initial, complaint. In multiple

contexts—involving both cases brought in federal court and

cases removed there—courts conceive of amendments to

pleadings as potentially jurisdiction-changing events. The

amended complaint becomes the operative one; and in tak-

ing the place of what has come before, it can either create

or destroy jurisdiction. Section 1367, as laid out above, fits

hand in glove with—indeed, embodies—that familiar ap-

proach. A post-removal amendment can divest a federal

court of its supplemental jurisdiction because—as the usual

procedural principle holds—jurisdiction follows from (and

only from) the operative pleading.

Begin from the beginning: The plaintiff is “the master of

the complaint,” and therefore controls much about her suit.

Caterpillar Inc. v. Williams, 482 U. S. 386, 398–399 (1987).

She gets to determine which substantive claims to bring

against which defendants. And in so doing, she can estab-

lish—or not—the basis for a federal court’s subject-matter

jurisdiction. She may, for example, name only defendants

who come from a different State, or instead add one from

her own State and thereby destroy diversity of citizenship.

See §1332(a). Or in cases like this one, she may decide to

plead federal-law claims, or instead to allege state-law

claims alone and thus ensure a state forum. See §1331; su-

pra, at 2 (describing the well-pleaded complaint rule).

And the plaintiff ’s control over those matters extends be-

yond the time her first complaint is filed. If a plaintiff

amends her complaint, the new pleading “supersedes” the

old one: The “original pleading no longer performs any func-

tion in the case.” 6 C. Wright, A. Miller, & M. Kane, Federal

Practice and Procedure §1476, pp. 636–637 (3d ed. 2010).

Or as we put the matter over a century ago: “When a peti-

tion is amended,” the “cause proceeds on the amended peti-

tion.” Washer v. Bullitt County, 110 U. S. 558, 562 (1884).

12 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

So changes in parties, or changes in claims, effectively re-

make the suit. And that includes its jurisdictional basis:

The reconfiguration accomplished by an amendment may

bring the suit either newly within or newly outside a federal

court’s jurisdiction.

That idea is the one Rockwell invoked, as earlier noted.

See supra, at 8–9. Recall the situation there considered:

“[A] plaintiff files a complaint in federal court and later vol-

untarily amends the complaint” to “withdraw[ ]” the allega-

tions supporting federal jurisdiction. Rockwell, 549 U. S.,

at 473–474. Should the suit proceed? “[C]ourts,” Rockwell

replied, “look to the amended complaint to determine juris-

diction.” Id., at 474. That complaint is now the operative

one; the old complaint has become irrelevant. So unless the

withdrawn allegations were “replaced by others” giving the

court adjudicatory power, the plaintiff ’s amendment “will

defeat jurisdiction.” Id., at 473. Or more specifically: If a

plaintiff files a suit in federal court based on federal claims

and later scraps those claims, the federal court cannot go

forward with a now all-state-claim suit. See id., at 473–

474. 5

That rule for original federal cases has a host of varia-

tions, each tying jurisdiction to an amended pleading. If, as

Rockwell spelled out, eliminating federal claims in such a

suit can destroy federal jurisdiction, the opposite is also

true: Adding federal claims can create federal jurisdiction

where it once was wanting. See, e.g., ConnectU LLC v.

——————

5 The Rockwell Court distinguished its rule from another, operating in

diversity cases, which evaluates a party’s citizenship (e.g., whether the

defendant is in fact from New York) at the time a suit is brought, and

never again later. See 549 U. S., at 473 (citing, e.g., Anderson v. Watt,

138 U. S. 694, 701 (1891)). That so-called time-of-filing rule, Rockwell

explained, concerns only the actual “state of things” relevant to jurisdic-

tion—meaning, the facts on the ground, rather than (as addressed here)

the claims and parties that the plaintiff includes in a complaint. 549

U. S., at 473; see 75 F. 4th 918, 922–923 (CA8 2023) (case below) (dis-

cussing that distinction).

Cite as: 604 U. S. ____ (2025) 13

Opinion of the Court

Zuckerberg, 522 F. 3d 82, 91 (CA1 2008) (holding that an

amended complaint, which “replaced the original complaint

lock, stock, and barrel,” conferred jurisdiction). And so too,

an amendment can either destroy or create jurisdiction in

an original diversity case. The addition of a non-diverse

party in such a case typically destroys diversity jurisdiction,

requiring the case’s dismissal. See Owen Equipment &

Erection Co. v. Kroger, 437 U. S. 365, 374–377 (1978) (stat-

ing that an amendment asserting claims against a non-

diverse party “destroy[s]” complete diversity “just as surely

as” joining that party in the first instance); see also, e.g.,

American Fiber & Finishing, Inc. v. Tyco Healthcare Group,

LP, 362 F. 3d 136, 139 (CA1 2004). 6 Conversely, the elimi-

nation of a non-diverse defendant by way of amendment en-

sures that a case can proceed in federal court, though it

could not have done so before. See Newman-Green, Inc. v.

Alfonzo-Larrain, 490 U. S. 826, 832–833 (1989). In short,

the rule in original cases that jurisdiction follows the

amended (i.e., now operative) pleading applies across the

board.

And still more: Similar rules have long applied in the re-

moval context. Not across the board, of course, else this

case would not have arisen: The very issue here is whether,

in a removed case (as in an original one), an amended com-

plaint dropping federal claims destroys jurisdiction. But in

two of the other situations discussed above, the rule in re-

moved cases is the same as the rule in original ones. 7 First,

——————

6 That general rule does not apply when an amendment merely substi-

tutes a successor-in-interest for the first-named defendant. In that situ-

ation, the former steps into the latter’s shoes, and the diversity jurisdic-

tion founded on the initial complaint thus continues. See Freeport-

McMoRan Inc. v. K N Energy, Inc., 498 U. S. 426, 428–429 (1991) (per

curiam).

7 To our knowledge, no appellate decision addresses whether in the fi-

nal situation discussed—when an amendment eliminates a non-diverse

party—the rule in removed cases similarly follows the rule in original

cases.

14 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

in removed cases too, amending a complaint to add a federal

claim creates federal jurisdiction when it did not previously

exist. So even if removing a case was improper because the

initial complaint did not contain a federal claim, the plain-

tiff ’s later assertion of such a claim establishes jurisdiction

going forward. See Pegram v. Herdrich, 530 U. S. 211, 215–

216, and n. 2 (2000); Bernstein v. Lind-Waldock & Co., 738

F. 2d 179, 185–186 (CA7 1984) (Posner, J.). The federal

court can thus resolve both the newly added federal-law

claim and the now supplemental state-law ones. See id., at

186–187. And second, in removed cases too, amending a

complaint to join a non-diverse party destroys diversity ju-

risdiction. So if such a joinder occurs after removal, the fed-

eral court must remand the case to the state court it began

in. See §1447(e); Powerex Corp. v. Reliant Energy Services,

Inc., 551 U. S. 224, 231–232 (2007). Once again, federal ju-

risdiction—or its absence—follows from the amended com-

plaint. 8

——————

8 Royal Canin offers up something of an exception: In both original and

removed cases, an amendment reducing the alleged amount-in-

controversy to below the statutory threshold—like a post-filing develop-

ment that makes recovering the needed amount impossible—will usually

not destroy diversity jurisdiction. See St. Paul Mercury Indemnity Co. v.

Red Cab Co., 303 U. S. 283, 289, 292 (1938); Brief for Petitioners 20. But

that rule is inapposite here, by virtue of its subject and function alike.

First, the rule more concerns a fact on the ground—that is, the value of

a suit—than it does the plaintiff ’s selection of claims and parties. So this

Court has viewed it as analogous to the time-of-filing rule applying to

citizenship, which also assesses a factual issue relevant to jurisdiction

only at the suit’s outset. See St. Paul Mercury, 303 U. S., at 294–295;

Rosado v. Wyman, 397 U. S. 397, 405, n. 6 (1970); supra, at 12, n. 5. Sec-

ond, the rule responds to the difficulties of assessing a suit’s value and

the likelihood that the calculation will change over the course of litiga-

tion. Especially given that the alleged amount-in-controversy does not

cap damages, “constant litigation” over the matter, having the potential

to alter a court’s jurisdiction, “would be wasteful.” Grupo Dataflux v.

Atlas Global Group, L. P., 541 U. S. 567, 580–581 (2004) (making the

same point about changes in citizenship). But as all the examples given

above show, we have never held such a concern to limit the effect of the

Cite as: 604 U. S. ____ (2025) 15

Opinion of the Court

The uniformity of that principle, as between original and

removed cases, is not surprising. The appropriateness of

federal jurisdiction—or the lack thereof—does not depend

on whether the plaintiff first filed suit in federal or state

court. Rather, it depends, in either event, on the substance

of the suit—the legal basis of the claims (federal or state?)

and the citizenship of the parties (diverse or not?). (That

focus on substance is indeed why original jurisdiction and

removal jurisdiction generally mirror each other in scope.

See §1441(a).) So in a removed no less than in an original

case, the rule that jurisdiction follows the operative plead-

ing serves a critical function. It too ensures that the case,

as it will actually be litigated, merits a federal forum.

And with all that recognized, the answer to the disputed

question here becomes yet more certain: On top of §1367, a

panoply of procedural rules shows that a post-removal

amendment excising all federal claims destroys federal ju-

risdiction. Under those rules, the presence of jurisdiction,

in removed as in original cases, hinges on the amended, now

operative pleading. By adding or subtracting claims or par-

ties, and thus reframing the suit, that pleading can alter a

federal court’s authority. And so it is here. When a plain-

tiff, after removal, cuts out all her federal-law claims,

federal-question jurisdiction dissolves. And with any fed-

eral anchor gone, supplemental jurisdiction over the resid-

ual state claims disappears as well. The operative pleading

no longer supports federal jurisdiction, and the federal

court must remand the case to the state court where it

started.

C

Royal Canin contends that this Court has twice before

reached the opposite conclusion—first, in Carnegie-Mellon

Univ. v. Cohill, 484 U. S. 343 (1988), and next in Rockwell,

——————

plaintiff ’s decision, as the master of her complaint, to add or subtract

claims or parties.

16 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

in a footnote to the analysis we have related above. See

supra, at 8–9, 12. But in each case, the relied-on passage is

extraneous to the Court’s holding and reasoning, and so

cannot bear the weight of Royal Canin’s argument.

Begin with Cohill, which shares the procedural posture

of this case but asked and answered a different question.

There, as here, the plaintiff filed a suit in state court, as-

serting both federal and state claims; the defendant re-

moved the suit to federal court; and the plaintiff then

dropped her federal claim and sought a remand. The Dis-

trict Court granted that request over the defendant’s objec-

tion. But in opposing that ruling, the defendant did not ar-

gue (à la Royal Canin) that the court should have held on to

the case. Rather, the defendant urged that the court should

have dismissed the case outright instead of remanding it.

(The difference mattered because the statute of limitations

had by then expired, and a dismissal would have ended the

suit.) The disputed issue was thus not about keeping the

case in federal court, but about two different ways of expel-

ling it. Or as Cohill put it: The question “present[ed] is

whether the District Court could relinquish jurisdiction

over the case only by dismissing it without prejudice or

whether the District Court could relinquish jurisdiction

over the case by remanding it to state court as well.” 484

U. S., at 351. We held that the federal court could remand

as well as dismiss, even though no statute then authorized

the former action. Id., at 357; see §1447(c) (now filling that

vacuum). Our reasoning, in that pre-§1367 era, focused on

the values served by supplemental jurisdiction, as set out

in Gibbs. “[E]conomy, convenience, fairness, and comity,”

we stated, “support[ ] giving a district court discretion to re-

mand when the exercise of [supplemental] jurisdiction is in-

appropriate.” Cohill, 484 U. S., at 351. So when a plaintiff

cuts her federal claims, the court should have a choice about

how best to get rid of the case.

In one spot, though, the Cohill Court intimated a view on

Cite as: 604 U. S. ____ (2025) 17

Opinion of the Court

whether the District Court also had discretion to retain the

suit. The sentence, pressed by Royal Canin, comes just be-

fore the Court’s statement of the question presented, quoted

above. See Brief for Petitioners 10–11, 19. It reads: “When

the single federal-law claim in the action was eliminated at

an early stage of the litigation, the District Court had a

powerful reason to choose not to continue to exercise juris-

diction.” Cohill, 484 U. S., at 351. In using the word

“choose,” Cohill suggested that the court, though having

strong cause to dismiss or remand, likewise had authority

to decide the case.

But that slender (and somewhat backhanded) dictum

cannot make us stop in our tracks. Nowhere did Cohill an-

alyze why a federal court could retain jurisdiction once an

amendment excised all federal-law claims. Cohill simply

supposed the court could and asserted as much, without

pausing to consider the matter. And that lack of scrutiny

reflected the issue’s lack of importance—not in today’s case

of course, but in that earlier one. As just explained, the

District Court in Cohill never thought to exercise jurisdic-

tion after the amendment; the issue in dispute was only

how to get rid of the action. So Cohill’s view about keeping

jurisdiction was gratuitous, and no sooner noted than

dropped. It supported neither the decision’s result nor its

values-based reasoning. And anyway, our own analysis is

based mainly on legal authorities post-dating Cohill—most

notably, §1367 and our Rockwell decision. See supra, at 6–

10, 12. Those later materials supersede whatever Cohill

presumed about exercising federal jurisdiction in a case like

this one. So by virtue of both what it decided and when it

arose, Cohill does not matter to the question before us.

That leaves the Rockwell footnote Royal Canin cites. As

earlier explained, the body of Rockwell examines what hap-

pens in an original case when a plaintiff amends a com-

plaint to expunge federal claims. See supra, at 8–9, 12. The

federal court, Rockwell held, loses jurisdiction. See 549

18 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

U. S., at 473–474. But in a two-sentence footnote, the Rock-

well Court said that the opposite rule applies in removed

cases. “[W]hen a defendant removes a case to federal court

based on the presence of a federal claim,” the footnote

stated, “an amendment eliminating the original basis for

federal jurisdiction generally does not defeat jurisdiction.”

Id., at 474, n. 6. That is because “removal cases raise

forum-manipulation concerns that simply do not exist when

it is the plaintiff who chooses a federal forum and then

pleads away jurisdiction through amendment.” Ibid. (em-

phasis in original). The footnote thus sets out exactly the

rule Royal Canin wants—and, in so doing, gives the com-

pany its best argument.

But still, the footnote is dictum, and does not control the

outcome here. Rockwell was an original federal case, not a

removed one. So the footnote’s assertion of a special rule

for removed cases was outside the issue being decided—or

more colloquially put, beside the point. The statement had

no bearing on the Court’s conclusion about jurisdiction in

original cases. Nor did it relate to the rationale supporting

that result. And to top it off, the footnote was itself barely

reasoned. 9 This Court has often stated that “drive-by juris-

——————

9 The footnote’s cursory reference to “forum-manipulation concerns”

fails on multiple levels. First, and most practically, plaintiffs can usually

forum shop without any resort to amendments. Except when a statute

of limitations has expired, a plaintiff need only voluntarily dismiss her

federal suit and file a new state-claim-only action in state court. So the

forum-manipulation benefit of the Rockwell footnote’s approach to re-

moved federal-question cases is likely quite marginal. Second, that ap-

proach conflicts with the one taken in the most comparable situation:

when in a removed diversity case, a plaintiff seeks a remand to state

court by means of adding a non-diverse party. As noted earlier, the rule

in that context is the standard one: Jurisdiction follows the amended

pleading—regardless of any (probably minor) forum-manipulation con-

cerns. See §1447(e); supra, at 14. Third and most important, those

policy-based concerns, even if significant, cannot trump a federal statute.

And as we elsewhere discuss—including in the next paragraph—§1367

Cite as: 604 U. S. ____ (2025) 19

Opinion of the Court

dictional rulings”—asserting or denying jurisdiction “with-

out elaboration,” or analysis of whether anything “turn[ed]

on” the ruling—should be accorded “no precedential effect.”

Wilkins v. United States, 598 U. S. 152, 160 (2023) (quoting

Arbaugh v. Y & H Corp., 546 U. S. 500, 511, 512 (2006);

alteration in original; Henderson v. Shinseki, 562 U. S. 428,

437 (2011)). The admonition goes double for throwaway

footnotes about jurisdictional issues neither raised in nor

conceivably relevant to a case. We therefore need not follow

the Rockwell footnote just because it exists; our adherence

instead depends on whether it withstands analysis. 10

And it does not, for all the reasons already given. A recap

here fittingly begins with Rockwell’s own core insight,

which points the opposite way. Federal courts, Rockwell

stated, “look to the amended complaint to determine juris-

diction.” 549 U. S., at 474. That rule, as earlier described,

explains a host of jurisdictional outcomes. See supra, at 11–

14. It operates in federal-question cases and diversity

cases, both to destroy and to create jurisdiction. And it can-

not give way, in a case like this one, just because the case

was removed from state to federal court. When, as here, a

complaint asserts both federal and state claims, and an

amendment strips out the federal ones, a district court’s ju-

risdiction depends on §1367. And §1367, as earlier shown,

makes no distinction between cases beginning in federal

court and cases removed there. See supra, at 8–9. If in the

former the amendment “defeat[s] jurisdiction,” as Rockwell

rightly held, 549 U. S., at 473, then so too in the latter. Re-

gardless of removal, the plaintiff ’s excision of her federal-

——————

offers no basis for treating original and removed cases differently, as the

Rockwell footnote proposes. See supra, at 8–9.

10 It is of course a much different thing for this Court to reach that

conclusion than for a lower court to do so. We do not at all fault any court

that relied on the Rockwell footnote to find jurisdiction in a case like this

one. Courts that did so simply took us at our word, in a way both under-

standable and appropriate.

20 ROYAL CANIN U. S. A., INC. v. WULLSCHLEGER

Opinion of the Court

law claims deprives the district court of its authority to de-

cide the state-law claims remaining.

III

For those reasons, the District Court here should have

remanded Wullschleger’s suit to state court. The earliest

version of that suit contained federal-law claims and there-

fore was properly removed to federal court. The additional

state-law claims were sufficiently related to the federal

ones to come within that court’s supplemental jurisdiction.

But when Wullschleger amended her complaint, the juris-

dictional analysis also changed. Her deletion of all federal

claims deprived the District Court of federal-question juris-

diction. And once that was gone, the court’s supplemental

jurisdiction over the state claims dissolved too. Wull-

schleger had reconfigured her suit to make it only about

state law. And so the suit became one for a state court.

We accordingly affirm the judgment of the Court of Ap-

peals for the Eighth Circuit.

It is so ordered.