(Slip Opinion) OCTOBER TERM, 2017 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 

SAS INSTITUTE INC. v. IANCU, DIRECTOR, UNITED 

STATES PATENT AND TRADEMARK OFFICE, ET AL. 

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR 

THE FEDERAL CIRCUIT 

No. 16–969. Argued November 27, 2017—Decided April 24, 2018 

Inter partes review allows private parties to challenge previously issued patent claims in an adversarial process before the Patent Office.

At the outset, a party must file a petition to institute review, 35 

U. S. C. §311(a), that identifies the challenged claims and the 

grounds for challenge with particularity, §312(a)(3). The patent owner, in turn, may file a response. §313. If the Director of the Patent 

Office determines “there is a reasonable likelihood that the petitioner

would prevail with respect to at least 1 of the claims challenged in 

the petition,” §314(a), he decides “whether to institute . . . review . . . 

pursuant to [the] petition,” §314(b). “If . . . review is instituted and 

not dismissed,” at the end of the litigation the Patent Trial and Appeal Board “shall issue a final written decision with respect to the patentability of any patent claim challenged by the petitioner.” §318(a).

Petitioner SAS sought review of respondent ComplementSoft’s 

software patent, alleging that all 16 of the patent’s claims were unpatentable. Relying on a Patent Office regulation recognizing a power of “partial institution,” 37 CFR §42.108(a), the Director instituted

review on some of the claims and denied review on the rest. The 

Board’s final decision addressed only the claims on which the Director had instituted review. On appeal, the Federal Circuit rejected 

SAS’s argument that §318(a) required the Board to decide the patentability of every claim challenged in the petition. 

Held: When the Patent Office institutes an inter partes review, it must

decide the patentability of all of the claims the petitioner has challenged. The plain text of §318(a) resolves this case. Its directive is 

both mandatory and comprehensive. The word “shall” generally imposes a nondiscretionary duty, and the word “any” ordinarily implies 
 

 

2 SAS INSTITUTE INC. v. IANCU 

Syllabus 

every member of a group. Thus, §318(a) means that the Board must 

address every claim the petitioner has challenged. The Director’s 

“partial institution” power appears nowhere in the statutory text. 

And both text and context strongly counsel against inferring such a 

power.

The statute envisions an inter partes review guided by the initial

petition. See §312(a)(3). Congress structured the process such that

the petitioner, not the Director, defines the proceeding’s contours. 

The ex parte reexamination statute shows that Congress knew exactly how to authorize the Director to investigate patentability questions

“[o]n his own initiative, and at any time,” §303(a). The inter partes

review statute indicates that the Director’s decision “whether” to institute review “pursuant to [the] petition” is a yes-or-no choice. 

§314(b). 

Section 314(a)’s requirement that the Director find “a reasonable

likelihood” that the petitioner will prevail on “at least 1 of the claims

challenged in the petition” suggests, if anything, a regime where a

reasonable prospect of success on a single claim justifies review of 

them all. Again, if Congress had wanted to adopt the Director’s 

claim-by-claim approach, it knew how to do so. See §304. Nor does it 

follow that, because §314(a) invests the Director with discretion on

the question whether to institute review, it also invests him with discretion regarding what claims that review will encompass. The rest 

of the statute confirms, too, that the petitioner’s petition, not the Director’s discretion, should guide the life of the litigation. See, e.g., 

§316(a)(8).

The Director suggests that a textual discrepancy between §314(a)—

which addresses whether to institute review based on claims found 

“in the petition”—and §318(a)—which addresses the Board’s final

resolution of the claims challenged “by the petitioner”—means that

the Director enjoys the power to institute a review covering fewer 

than all of the claims challenged in the petition. However, the statute’s winnowing mechanism—which allows a patent owner to concede one part of a petitioner’s challenge and “[c]ancel any challenged 

patent claim,” §316(d)(1)(A)—fully explains why Congress adopted

the slightly different language. 

The Director’s policy argument—that partial institution is efficient 

because it permits the Board to focus on the most promising challenges and avoid spending time and resources on others—is properly

addressed to Congress, not this Court. And the Director’s asserted 

“partial institution” power, which is wholly unmentioned in the statute, is not entitled to deference under Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U. S. 837. Finally, notwithstanding §314(d)—which makes the Director’s determination 
 

Cite as: 584 U. S. ____ (2018) 3 

Syllabus 

whether to institute an inter partes review “final and nonappealable”—judicial review remains available consistent with the Administrative Procedure Act to ensure that the Patent Office does not exceed its statutory bounds. Cuozzo Speed Technologies, LLC v. Lee, 

579 U. S. ___, distinguished. Pp. 4–14. 

825 F. 3d 1341, reversed and remanded. 

GORSUCH, J., delivered the opinion of the Court, in which ROBERTS, 

C. J., and KENNEDY, THOMAS, and ALITO, JJ., joined. GINSBURG, J., filed 

a dissenting opinion, in which BREYER, SOTOMAYOR, and KAGAN, JJ., 

joined. BREYER, J., filed a dissenting opinion, in which GINSBURG and 

SOTOMAYOR, JJ., joined, and in which KAGAN, J., joined except as to 

Part III–A. 
 

 

_________________ 

_________________ 

 

 

Cite as: 584 U. S. ____ (2018) 1 

Opinion of the Court 

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. 16–969 

SAS INSTITUTE INC., PETITIONER v. ANDREI IANCU,
 

AS DIRECTOR, UNITED STATES PATENT
 

AND TRADEMARK OFFICE, ET AL. 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE FEDERAL CIRCUIT
 

[April 24, 2018]

 JUSTICE GORSUCH delivered the opinion of the Court. 

A few years ago Congress created “inter partes review.”

The new procedure allows private parties to challenge

previously issued patent claims in an adversarial process

before the Patent Office that mimics civil litigation. Recently, the Court upheld the inter partes review statute

against a constitutional challenge. Oil States Energy 

Services, LLC v. Greene’s Energy Group, LLC, ante, p. ___.

Now we take up a question concerning the statute’s operation. When the Patent Office initiates an inter partes 

review, must it resolve all of the claims in the case, or may 

it choose to limit its review to only some of them? The 

statute, we find, supplies a clear answer: the Patent Office 

must “issue a final written decision with respect to the 

patentability of any patent claim challenged by the petitioner.” 35 U. S. C. §318(a) (emphasis added). In this 

context, as in so many others, “any” means “every.” The 

agency cannot curate the claims at issue but must decide 

them all. 

“To promote the Progress of Science and useful Arts,” 
 

 

2 SAS INSTITUTE INC. v. IANCU 

Opinion of the Court 

Congress long ago created a patent system granting inventors rights over the manufacture, sale, and use of their 

inventions. U. S. Const., Art. I, §8, cl. 8; see 35 U. S. C. 

§154(a)(1). To win a patent, an applicant must (among 

other things) file “claims” that describe the invention and 

establish to the satisfaction of the Patent Office the invention’s novelty and nonobviousness. See §§102, 103, 112(b), 

131; Cuozzo Speed Technologies, LLC v. Lee, 579 U. S. ___, 

___–___ (2016) (slip op., at 2–3). 

Sometimes, though, bad patents slip through. Maybe

the invention wasn’t novel, or maybe it was obvious all 

along, and the patent owner shouldn’t enjoy the special 

privileges it has received. To remedy these sorts of problems, Congress has long permitted parties to challenge the 

validity of patent claims in federal court. See §§282(b)(2)– 

(3). More recently, Congress has supplemented litigation

with various administrative remedies. The first of these 

was ex parte reexamination. Anyone, including the Director of the Patent Office, can seek ex parte reexamination 

of a patent claim. §§302, 303(a). Once instituted, though,

an ex parte reexamination follows essentially the same

inquisitorial process between patent owner and examiner 

as the initial Patent Office examination. §305. Later, 

Congress supplemented ex parte reexamination with inter 

partes reexamination. Inter partes reexamination (since 

repealed) provided a slightly more adversarial process,

allowing a third party challenger to submit comments

throughout the proceeding. §314(b)(2) (2006 ed.) (repealed). But otherwise it too followed a more or less inquisitorial course led by the Patent Office. §314(a). Apparently unsatisfied with this approach, in 2011 Congress

repealed inter partes reexamination and replaced it with

inter partes review. See 35 U. S. C. §§311–319 (2012 ed.). 

The new inter partes review regime looks a good deal 

more like civil litigation. At its outset, a party must file “a

petition to institute an inter partes review of [a] patent.” 
 

Cite as: 584 U. S. ____ (2018) 3 

Opinion of the Court 

§311(a). The petition “may request to cancel as unpatentable 1 or more claims of [the] patent” on the ground that 

the claims are obvious or not novel. §311(b); see §§102 

and 103. In doing so, the petition must identify “each

claim challenged,” the grounds for the challenge, and the 

evidence supporting the challenge. §312(a)(3). The patent 

owner, in turn, may respond with “a preliminary response 

to the petition” explaining “why no inter partes review 

should be instituted.” §313. With the parties’ submissions

before him, the Director then decides “whether to institute 

an inter partes review . . . pursuant to [the] petition.”

§314(b). (In practice, the agency’s Patent Trial and Appeal

Board exercises this authority on behalf of the Director,

see 37 CFR §42.4(a) (2017).) Before instituting review, the 

Director must determine, based on the parties’ papers, 

“that there is a reasonable likelihood that the petitioner 

would prevail with respect to at least 1 of the claims challenged in the petition.” 35 U. S. C. §314(a). 

Once the Director institutes an inter partes review, the

matter proceeds before the Board with many of the usual 

trappings of litigation. The parties conduct discovery and 

join issue in briefing and at an oral hearing. §§316(a)(5), 

(6), (8), (10), (13). During the course of the case, the patent owner may seek to amend its patent or to cancel one

or more of its claims. §316(d). The parties may also settle 

their differences and seek to end the review. §317. But 

“[i]f an inter partes review is instituted and not dismissed,” at the end of the litigation the Board “shall issue 

a final written decision with respect to the patentability of

any patent claim challenged by the petitioner.” §318(a).

Our case arose when SAS sought an inter partes review

of ComplementSoft’s software patent. In its petition, SAS

alleged that all 16 of the patent’s claims were unpatentable for various reasons. The Director (in truth the Board 

acting on the Director’s behalf) concluded that SAS was

likely to succeed with respect to at least one of the claims 
 

 

4 SAS INSTITUTE INC. v. IANCU 

Opinion of the Court 

and that an inter partes review was therefore warranted. 

But instead of instituting review on all of the claims challenged in the petition, the Director instituted review on 

only some (claims 1 and 3–10) and denied review on the 

rest. The Director did all this on the strength of a Patent

Office regulation that purported to recognize a power of

“partial institution,” claiming that “[w]hen instituting 

inter partes review, the [Director] may authorize the review to proceed on all or some of the challenged claims and 

on all or some or the grounds of unpatentability asserted

for each claim.” 37 CFR §42.108(a). At the end of litigation, the Board issued a final written decision finding 

claims 1, 3, and 5–10 to be unpatentable while upholding 

claim 4. But the Board’s decision did not address the 

remaining claims on which the Director had refused

review. 

That last fact led SAS to seek review in the Federal 

Circuit. There SAS argued that 35 U. S. C. §318(a) required the Board to decide the patentability of every claim 

SAS challenged in its petition, not just some. For its part,

the Federal Circuit rejected SAS’s argument over a vigorous dissent by Judge Newman. SAS Institute, Inc. v. 

ComplementSoft, LLC, 825 F. 3d 1341 (2016). We granted 

certiorari to decide the question ourselves. 581 U. S. ___ 

(2017).

We find that the plain text of §318(a) supplies a ready 

answer. It directs that “[i]f an inter partes review is instituted and not dismissed under this chapter, the [Board] 

shall issue a final written decision with respect to the 

patentability of any patent claim challenged by the petitioner . . . .” §318(a) (emphasis added). This directive is 

both mandatory and comprehensive. The word “shall” 

generally imposes a nondiscretionary duty. See Lexecon 

Inc. v. Milberg Weiss Bershad Hynes & Lerach, 523 U. S. 

26, 35 (1998). And the word “any” naturally carries “an

expansive meaning.” United States v. Gonzales, 520 U. S. 
 

Cite as: 584 U. S. ____ (2018) 5 

Opinion of the Court 

1, 5 (1997). When used (as here) with a “singular noun in

affirmative contexts,” the word “any” ordinarily “refer[s] to

a member of a particular group or class without distinction or limitation” and in this way “impl[ies] every member 

of the class or group.” Oxford English Dictionary (3d ed.,

Mar. 2016), www.oed.com/view/Entry/8973 (OED) (emphasis added) (all Internet materials as last visited Apr. 20, 

2018). So when §318(a) says the Board’s final written

decision “shall” resolve the patentability of “any patent 

claim challenged by the petitioner,” it means the Board 

must address every claim the petitioner has challenged.

That would seem to make this an easy case. Where a 

statute’s language carries a plain meaning, the duty of an

administrative agency is to follow its commands as written, not to supplant those commands with others it may

prefer. Social Security Bd. v. Nierotko, 327 U. S. 358, 369 

(1946). Because SAS challenged all 16 claims of ComplementSoft’s patent, the Board in its final written decision 

had to address the patentability of all 16 claims. Much as 

in the civil litigation system it mimics, in an inter partes

review the petitioner is master of its complaint and normally entitled to judgment on all of the claims it raises, 

not just those the decisionmaker might wish to address. 

The Director replies that things are not quite as simple

as they seem. Maybe the Board has to decide every claim 

challenged by the petitioner in an inter partes review.

But, he says, that doesn’t mean every challenged claim 

gains admission to the review process. In the Director’s 

view, he retains discretion to decide which claims make it 

into an inter partes review and which don’t. The trouble 

is, nothing in the statute says anything like that. The 

Director’s claimed “partial institution” power appears 

nowhere in the text of §318, or anywhere else in the statute for that matter. And what can be found in the statutory 

text and context strongly counsels against the Director’s

view. 
 

 

6 SAS INSTITUTE INC. v. IANCU 

Opinion of the Court 

Start where the statute does. In its very first provision, 

the statute says that a party may seek inter partes review 

by filing “a petition to institute an inter partes review.” 

§311(a). This language doesn’t authorize the Director to 

start proceedings on his own initiative. Nor does it contemplate a petition that asks the Director to initiate whatever kind of inter partes review he might choose. Instead, 

the statute envisions that a petitioner will seek an inter 

partes review of a particular kind—one guided by a petition describing “each claim challenged” and “the grounds

on which the challenge to each claim is based.” §312(a)(3).

From the outset, we see that Congress chose to structure a 

process in which it’s the petitioner, not the Director, who 

gets to define the contours of the proceeding. And “[j]ust

as Congress’ choice of words is presumed to be deliberate” 

and deserving of judicial respect, “so too are its structural 

choices.” University of Tex. Southwestern Medical Center 

v. Nassar, 570 U. S. 338, 353 (2013). 

It’s telling, too, to compare this structure with what

came before. In the ex parte reexamination statute, Congress embraced an inquisitorial approach, authorizing the 

Director to investigate a question of patentability “[o]n his

own initiative, and at any time.” §303(a). If Congress had 

wanted to give the Director similar authority over the 

institution of inter partes review, it knew exactly how to

do so—it could have simply borrowed from the statute

next door. But rather than create (another) agency-led, 

inquisitorial process for reconsidering patents, Congress

opted for a party-directed, adversarial process. Congress’s

choice to depart from the model of a closely related statute

is a choice neither we nor the agency may disregard. See 

Nassar, supra, at 353–354. 

More confirmation comes as we move to the point of 

institution. Here the statute says the Director must decide “whether to institute an inter partes review . . . pursuant to a petition.” §314(b). The Director, we see, is 
 

Cite as: 584 U. S. ____ (2018) 7 

Opinion of the Court 

given only the choice “whether” to institute an inter partes 

review. That language indicates a binary choice—either 

institute review or don’t. And by using the term “pursuant to,” Congress told the Director what he must say yes 

or no to: an inter partes review that proceeds “[i]n accordance with” or “in conformance to” the petition. OED, 

www.oed.com/view/Entry/155073. Nothing suggests the

Director enjoys a license to depart from the petition and 

institute a different inter partes review of his own design. 

To this the Director replies by pointing to another part

of §314. Section 314(a) provides that the Director may not

authorize an inter partes review unless he determines

“there is a reasonable likelihood” the petitioner will prevail on “at least 1 of the claims challenged in the petition.” 

The Director argues that this language requires him to

“evaluate claims individually” and so must allow him to

institute review on a claim-by-claim basis as well. Brief 

for Federal Respondent 28. But this language, if anything, suggests just the opposite. Section 314(a) does not 

require the Director to evaluate every claim individually.

Instead, it simply requires him to decide whether the

petitioner is likely to succeed on “at least 1” claim. Once 

that single claim threshold is satisfied, it doesn’t matter

whether the petitioner is likely to prevail on any additional 

claims; the Director need not even consider any other 

claim before instituting review. Rather than contemplate 

claim-by-claim institution, then, the language anticipates 

a regime where a reasonable prospect of success on a 

single claim justifies review of all.

Here again we know that if Congress wanted to adopt 

the Director’s approach it knew exactly how to do so. The 

ex parte reexamination statute allows the Director to

assess whether a request raises “a substantial new question of patentability affecting any claim” and (if so) to 

institute reexamination limited to “resolution of the question.” §304 (emphasis added). In other words, that stat-
 

 

 

8 SAS INSTITUTE INC. v. IANCU 

Opinion of the Court 

ute allows the Director to institute proceedings on a claimby-claim and ground-by-ground basis. But Congress didn’t 

choose to pursue that known and readily available approach here. And its choice to try something new must be

given effect rather than disregarded in favor of the comfort

of what came before. See Nassar, supra, at 353–354. 

Faced with this difficulty, the Director tries another 

tack. He points to the fact that §314(a) doesn’t require

him to institute an inter partes review even after he finds

the “reasonable likelihood” threshold met with respect to 

one claim. Whether to institute proceedings upon such a 

finding, he says, remains a matter left to his discretion. 

See Cuozzo, 579 U. S., at ___ (slip op., at 9). But while 

§314(a) invests the Director with discretion on the question whether to institute review, it doesn’t follow that the 

statute affords him discretion regarding what claims that 

review will encompass. The text says only that the Director can decide “whether” to institute the requested review—not “whether and to what extent” review should 

proceed. §314(b).

The rest of the statute confirms, too, that the petitioner’s petition, not the Director’s discretion, is supposed to

guide the life of the litigation. For example, §316(a)(8) 

tells the Director to adopt regulations ensuring that, “after

an inter partes review has been instituted,” the patent

owner will file “a response to the petition.” Surely it

would have made little sense for Congress to insist on a 

response to the petition if, in truth, the Director enjoyed

the discretion to limit the claims under review. What’s the 

point, after all, of answering claims that aren’t in the 

proceeding? If Congress had meant to afford the Director

the power he asserts, we would have expected it to instruct him to adopt regulations requiring the patent owner

to file a response to the Director’s institution notice or to 

the claims on which the Director instituted review. Yet we 

have nothing like that here. And then and again there is 
 

 

Cite as: 584 U. S. ____ (2018) 9 

Opinion of the Court 

§318(a). At the end of the proceeding, §318(a) categorically 

commands the Board to address in its final written 

decision “any patent claim challenged by the petitioner.”

In all these ways, the statute tells us that the petitioner’s

contentions, not the Director’s discretion, define the scope 

of the litigation all the way from institution through to

conclusion. 

The Director says we can find at least some hint of the 

discretion he seeks by comparing §314(a) and §318(a). He 

notes that, when addressing whether to institute review at 

the beginning of the litigation, §314(a) says he must focus

on the claims found “in the petition”; but when addressing

what claims the Board must address at the end of the 

litigation, §318(a) says it must resolve the claims challenged “by the petitioner.” According to the Director, this 

(slight) linguistic discrepancy means the claims the Board

must address in its final decision are not necessarily the 

same as those identified in the petition. And the only

possible explanation for this arrangement, the Director 

submits, is that he must enjoy the (admittedly implicit) 

power to institute an inter partes review that covers fewer 

than all of the claims challenged in the petition.

We just don’t see it. Whatever differences they might

display, §314(a) and §318(a) both focus on the petitioner’s

contentions and, given that, it’s difficult to see how they

might be read to give the Director power to decide what 

claims are at issue. Particularly when there’s a much 

simpler and sounder explanation for the statute’s wording.

As we’ve seen, a patent owner may move to “[c]ancel any 

challenged patent claim” during the course of an inter 

partes review, effectively conceding one part of a petitioner’s challenge. §316(d)(1)(A). Naturally, then, the claims

challenged “in the petition” will not always survive to the

end of the case; some may drop out thanks to the patent 

owner’s actions. And in that light it is plain enough why 

Congress provided that only claims still challenged “by the 
 

 

 

 

10 SAS INSTITUTE INC. v. IANCU 

Opinion of the Court 

petitioner” at the litigation’s end must be addressed in the

Board’s final written decision. The statute’s own winnowing mechanism fully explains why Congress adopted 

slightly different language in §314(a) and §318(a). We 

need not and will not invent an atextual explanation for 

Congress’s drafting choices when the statute’s own terms

supply an answer. See United States v. Ron Pair Enterprises, Inc., 489 U. S. 235, 240–241 (1989) (“[A]s long as

the statutory scheme is coherent and consistent, there

generally is no need for a court to inquire beyond the plain 

language of the statute”).

Moving past the statute’s text and context, the Director

attempts a policy argument. He tells us that partial institution is efficient because it permits the Board to focus on

the most promising challenges and avoid spending time 

and resources on others. Brief for Federal Respondent 35– 

36; see also post, at 1 (GINSBURG, J., dissenting); post, at 

7–8 (BREYER, J., dissenting). SAS responds that all patent

challenges usually end up being litigated somewhere, and 

that partial institution creates inefficiency by requiring

the parties to litigate in two places instead of one—the 

Board for claims the Director chooses to entertain and a 

federal court for claims he refuses. Indeed, SAS notes, the 

government itself once took the same view, arguing that 

partial institution “‘undermine[s] the Congressional efficiency goal’” for this very reason. Brief for Petitioner 30. 

Each side offers plausible reasons why its approach might

make for the more efficient policy. But who should win 

that debate isn’t our call to make. Policy arguments are 

properly addressed to Congress, not this Court. It is 

Congress’s job to enact policy and it is this Court’s job to 

follow the policy Congress has prescribed. And whatever 

its virtues or vices, Congress’s prescribed policy here is 

clear: the petitioner in an inter partes review is entitled to 
Cite as: 584 U. S. ____ (2018) 11 

Opinion of the Court 

a decision on all the claims it has challenged.*

That leaves the Director to suggest that, however this

Court might read the statute, he should win anyway 

because of Chevron U. S. A. Inc. v. Natural Resources 

Defense Council, Inc., 467 U. S. 837 (1984). Even though

the statute says nothing about his asserted “partial institution” power, the Director says the statute is at least 

ambiguous on the propriety of the practice and so we

should leave the matter to his judgment. For its part, SAS

replies that we might use this case as an opportunity to 

abandon Chevron and embrace the “‘impressive body’” of 

pre-Chevron law recognizing that “‘the meaning of a statutory term’” is properly a matter for “‘judicial [rather 

than] administrative judgment.’” Brief for Petitioner 41 

(quoting Pittston Stevedoring Corp. v. Dellaventura, 544 

F. 2d 35, 49 (CA2 1976) (Friendly, J.)).

 But whether Chevron should remain is a question we 

may leave for another day. Even under Chevron, we owe 

an agency’s interpretation of the law no deference unless,

after “employing traditional tools of statutory construction,” we find ourselves unable to discern Congress’s 

—————— 

* JUSTICE GINSBURG suggests the Director might yet avoid this command by refusing to review a petition he thinks too broad while signaling his willingness to entertain one more tailored to his sympathies. 

Post, at 1 (dissenting opinion). We have no occasion today to consider

whether this stratagem is consistent with the statute’s demands. See 

Cuozzo Speed Technologies, LLC v. Lee, 579 U. S. ___, ___ (2016) (slip

op., at 11) (noting that courts may invalidate “ ‘shenanigans’ ” by the 

Director that are “outside [his] statutory limits”); CAB v. Delta Air 

Lines, Inc., 367 U. S. 316, 328 (1961) (questioning an agency’s “power to 

do indirectly what it cannot do directly”). But even assuming (without

granting) the law would tolerate this tactic, it would show only that a

lawful means exists for the Director to achieve his policy aims—not 

that he “should be allowed to improvise on the powers granted by 

Congress” by devising an extralegal path to the same goal. Id., at 330. 

That an agency’s improvisation might be thought by some more expedient than what the law allows, post, at 1, does nothing to commend it

either, for lawful ends do not justify unlawful means. 
 

12 SAS INSTITUTE INC. v. IANCU 

Opinion of the Court 

meaning. 467 U. S., at 843, n. 9. And after applying

traditional tools of interpretation here, we are left with no 

uncertainty that could warrant deference. The statutory 

provisions before us deliver unmistakable commands. The 

statute hinges inter partes review on the filing of a petition challenging specific patent claims; it makes the petition the centerpiece of the proceeding both before and after

institution; and it requires the Board’s final written decision to address every claim the petitioner presents for 

review. There is no room in this scheme for a wholly 

unmentioned “partial institution” power that lets the

Director select only some challenged claims for decision. 

The Director may (today) think his approach makes for 

better policy, but policy considerations cannot create an

ambiguity when the words on the page are clear. See SEC 

v. Sloan, 436 U. S. 103, 116–117 (1978). Neither may we 

defer to an agency official’s preferences because we imagine some “hypothetical reasonable legislator” would have 

favored that approach. Post, at 9 (BREYER, J., dissenting). 

Our duty is to give effect to the text that 535 actual legislators (plus one President) enacted into law.

At this point, only one final question remains to resolve. 

Even if the statute forbids his partial institution practice,

the Director suggests we lack the power to say so. By way

of support, he points to §314(d) and our decision in Cuozzo, 

579 U. S. ___. Section 314(d) says that the “determination 

by the Director whether to institute an inter partes review

under this section shall be final and nonappealable.” In 

Cuozzo, we held that this provision prevented courts from

entertaining an argument that the Director erred in instituting an inter partes review of certain patent claims. Id., 

at ___–___ (slip op., at 7–12). The Director reads these 

authorities as foreclosing judicial review of any legal 

question bearing on the institution of inter partes review—including whether the statute permits his “partial

institution” practice. 
 

Cite as: 584 U. S. ____ (2018) 13 

Opinion of the Court 

But this reading overreads both the statute and our

precedent. As Cuozzo recognized, we begin with “the

‘strong presumption’ in favor of judicial review.” Id., at 

___ (slip op., at 9). To overcome that presumption, Cuozzo 

explained, this Court’s precedents require “clear and 

convincing indications” that Congress meant to foreclose

review. Id., at ___ (slip op., at 10) (internal quotation

marks omitted). Given the strength of this presumption 

and the statute’s text, Cuozzo concluded that §314(d) 

precludes judicial review only of the Director’s “initial

determination” under §314(a) that “there is a ‘reasonable 

likelihood’ that the claims are unpatentable on the

grounds asserted” and review is therefore justified. Id., at 

___ (slip op., at 9); see id., at ___ (slip op., at 12) (review 

unavailable “where a patent holder merely challenges the 

Patent Office’s ‘determin[ation] that the information 

presented in the petition . . . shows that there is a reasonable likelihood’ of success ‘with respect to at least 1 of the 

claims challenged’”); ibid. (claim that a “petition was not 

pleaded ‘with particularity’ under §312 is little more than 

a challenge to the Patent Office’s conclusion, under

§314(a), that the ‘information presented in the petition’ 

warranted review”). In fact, Cuozzo proceeded to emphasize that §314(d) does not “enable the agency to act outside

its statutory limits.” Id., at ___ (slip op., at 11). If a party 

believes the Patent Office has engaged in “‘shenanigans’” 

by exceeding its statutory bounds, judicial review remains

available consistent with the Administrative Procedure 

Act, which directs courts to set aside agency action “not in 

accordance with law” or “in excess of statutory jurisdiction, authority, or limitations.” Ibid.; 5 U. S. C. 

§§706(2)(A), (C).

And that, of course, is exactly the sort of question we are 

called upon to decide today. SAS does not seek to challenge the Director’s conclusion that it showed a “reasonable likelihood” of success sufficient to warrant “insti-
 

 

14 SAS INSTITUTE INC. v. IANCU 

Opinion of the Court 

tut[ing] an inter partes review.” 35 U. S. C. §§314(a), (d).

No doubt SAS remains very pleased with the Director’s 

judgment on that score. Instead, SAS contends that the 

Director exceeded his statutory authority by limiting the

review to fewer than all of the claims SAS challenged. 

And nothing in §314(d) or Cuozzo withdraws our power to

ensure that an inter partes review proceeds in accordance

with the law’s demands. 

Because everything in the statute before us confirms

that SAS is entitled to a final written decision addressing 

all of the claims it has challenged and nothing suggests we

lack the power to say so, the judgment of the Federal

Circuit is reversed and the case is remanded for further 

proceedings consistent with this opinion. 

So ordered. 
_________________ 

_________________ 

 

Cite as: 584 U. S. ____ (2018) 1 

GINSBURG, J., dissenting 

SUPREME COURT OF THE UNITED STATES 

No. 16–969 

SAS INSTITUTE INC., PETITIONER v. ANDREI IANCU,
 

AS DIRECTOR, UNITED STATES PATENT
 

AND TRADEMARK OFFICE, ET AL. 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE FEDERAL CIRCUIT
 

[April 24, 2018]

 JUSTICE GINSBURG, with whom JUSTICE BREYER, 

JUSTICE SOTOMAYOR, and JUSTICE KAGAN join, dissenting. 

Given the Court’s wooden reading of 35 U. S. C. §318(a),

and with “no mandate to institute [inter partes] review” at 

all, Cuozzo Speed Technologies, LLC v. Lee, 579 U. S. ___, 

___ (2016) (slip op., at 9), the Patent Trial and Appeal

Board could simply deny a petition containing challenges 

having no “reasonable likelihood” of success, §314(a).

Simultaneously, the Board might note that one or more

specified claims warrant reexamination, while others 

challenged in the petition do not. Petitioners would then 

be free to file new or amended petitions shorn of challenges 

the Board finds unworthy of inter partes review. Why

should the statute be read to preclude the Board’s more 

rational way to weed out insubstantial challenges? For 

the reasons stated by JUSTICE BREYER, the Court’s opinion 

offers no persuasive answer to that question, and no cause 

to believe Congress wanted the Board to spend its time so 

uselessly. 
_________________ 

_________________ 

Cite as: 584 U. S. ____ (2018) 1 

BREYER, J., dissenting 

SUPREME COURT OF THE UNITED STATES 

No. 16–969 

SAS INSTITUTE INC., PETITIONER v. ANDREI IANCU,
 

AS DIRECTOR, UNITED STATES PATENT
 

AND TRADEMARK OFFICE, ET AL. 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE FEDERAL CIRCUIT
 

[April 24, 2018]

 JUSTICE BREYER, with whom JUSTICE GINSBURG and 

JUSTICE SOTOMAYOR join, and with whom JUSTICE KAGAN 

joins except as to Part III–A, dissenting. 

This case requires us to engage in a typical judicial 

exercise, construing a statute that is technical, unclear,

and constitutes a minor procedural part of a larger administrative scheme. I would follow an interpretive technique

that judges often use in such cases. Initially, using “traditional tools of statutory construction,” INS v. CardozaFonseca, 480 U. S. 421, 446 (1987), I would look to see

whether the relevant statutory phrase is ambiguous or 

leaves a gap that Congress implicitly delegated authority 

to the agency to fill. Chevron U. S. A. Inc. v. Natural 

Resources Defense Council, Inc., 467 U. S. 837, 842–843 

(1984). If so, I would look to see whether the agency’s 

interpretation is reasonable. Id., at 843. Because I believe there is such a gap and because the Patent Office’s 

interpretation of the ambiguous phrase is reasonable, I 

would conclude that the Patent Office’s interpretation is

lawful. 

I 

The majority sets out the statutory framework that 

establishes “inter partes review.” See ante, at 2–3; 35 
 

 

 

2 SAS INSTITUTE INC. v. IANCU 

BREYER, J., dissenting 

U. S. C. §§311–319. An example will help the reader keep 

that framework in mind. Suppose the Patent Office issues

a patent containing, say, 16 different claims. A challenger,

believing the patent is invalid, seeks to invoke the inter 

partes review procedure.

The statutory chapter entitled “Inter partes review”

explains just how this is to be done. See §§311–319. First, 

the challenger files a petition requesting “cancel[lation]” of 

one or more of the patent claims as “unpatentable” because “prior art” shows, for example, that they are not

“novel.” §311(b); see §§102, 103. That petition must detail 

the grounds for the challenge and the supporting evidence,

along with providing certain technical information. §312. 

Second, the patent owner may file a “preliminary response” to the petition. §313.

Third, the Director of the Patent Office will decide 

whether to “institute” inter partes review. §314. The 

statute specifies that the Director “may not authorize an 

inter partes review to be instituted unless the Director

determines . . . that there is a reasonable likelihood that 

the petitioner would prevail with respect to at least 1 of 

the claims challenged in the petition.” §314(a). Thus, in 

my example, if the Director determines that none of the 16 

challenges in the petition has likely merit, he cannot 

institute an inter partes review. Even if there is one 

potentially meritorious challenge, we have said that the 

statute contains “no mandate to institute review,” so the 

Director still has discretion to deny a petition. Cuozzo 

Speed Technologies, LLC v. Lee, 579 U. S. ___, ___ (2016) 

(slip op., at 9). We have also held that the Director’s 

decision whether to institute review is normally not reviewable. Id., at ___–___ (slip op., at 11–12). 

The Director, by regulation, has delegated the power to 

institute review to the Patent Trial and Appeal Board. 37 

CFR §42.4(a) (2017). And the Director has further provided

by regulation that where a petition challenges several 
 

Cite as: 584 U. S. ____ (2018) 3 

BREYER, J., dissenting 

patent claims (say, all 16 claims in my example), “the

Board may authorize the review to proceed on all or some 

of the challenged claims.” §42.108(a) (emphasis added).

Thus, where some, but not all, of the challenges have 

likely merit (say, 1 of the 16 has likely merit and the

others are close to frivolous), the Board is free to conduct 

inter partes review only as to the challenge with likely

merit. 

Fourth, the statute next describes the relation of a 

petition for review and an instituted review to other proceedings involving the challenged patent. §315. Fifth, the 

statute describes what happens once the Board begins its

inter partes review, including how the Board is to take 

evidence and make its decisions, §316, and the nature and

effect of settlements, §317.

Sixth, the statute sets forth the section primarily at

issue here, which describes what happens at the end of the 

process. It says: 

“Final Written Decision. If an inter partes review is 

instituted and not dismissed under this chapter, the

Patent Trial and Appeal Board shall issue a final 

written decision with respect to the patentability of 

any patent claim challenged by the petitioner and any 

new claim added under section 316(d).” §318(a) (emphasis added). 

Finally, the chapter says that a “party dissatisfied with

the final written decision . . . may appeal the decision” to

the U. S. Court of Appeals for the Federal Circuit. §319;

see §141(c).

Thus, going through this process, if a petitioner files a

petition challenging 16 claims and the Board finds that 

the challenges to 15 of the claims are frivolous, the Board 

may then, as it interprets the statute, begin and proceed 

through the inter partes review process as to the remaining claim, number 16, but not in respect to the other 15 
 

4 SAS INSTITUTE INC. v. IANCU 

BREYER, J., dissenting 

claims. Eventually the Board will produce a “final written 

decision” as to the patentability of claim number 16, which 

decision the challenger (or the patentee) can appeal to the

Federal Circuit. 

II 

Now let us return to the question at hand, the meaning

of the phrase “any patent claim challenged by the petitioner” in §318(a). Do those words unambiguously refer, 

as the majority believes, to “any patent claim challenged 

by the petitioner” in the petitioner’s original petition? The 

words “in the petitioner’s original petition” do not appear 

in the statute. And the words that do appear, “any patent 

claim challenged by the petitioner,” could be modified by 

using different words that similarly do not appear, for 

example, the words “in the inter partes review proceeding.” But without added words, the phrase “challenged by

the petitioner” does not tell us whether the relevant challenge is one made in the initial petition or only one made

in the inter partes review proceeding itself. And, linguistically speaking, there is as much reason to fill that gap 

with reference to the claims still being challenged in the 

proceeding itself as there is to fill it with reference to 

claims that were initially challenged in the petition but 

which the Board weeded out before the inter partes review 

proceeding began.

Which reading we give the statute makes a difference. 

The first reading, the majority’s reading, means that in

my example, the Board must consider and write a final,

and appealable, see §319, decision in respect to the challenges to all 16 claims, including the 15 frivolous challenges. 

The second reading requires the Board to write a final,

appealable decision only in respect to the challenge to the 

claim (number 16 in my example) that survived the

Board’s initial screening, namely, in my example, the one

challenge in respect to which the Board found a “reason-
 

Cite as: 584 U. S. ____ (2018) 5 

BREYER, J., dissenting 

able likelihood that the petitioner would prevail.” §314(a). 

I cannot find much in the statutory context to support 

the majority’s claim that the statutory words “claim challenged by the petitioner” refer unambiguously to claims

challenged initially in the petition. After all, the majority 

agrees that they do not refer to claims that initially were

challenged in the petition but were later settled or withdrawn. Ante, at 9–10; see §316(d)(1)(A) (allowing the 

patent owner to cancel a challenged patent claim during 

inter partes review); §317 (addressing settlement). The 

majority says that weeded-out challenges, unlike settled 

matters or canceled claims, involve claims that are still 

being “challenged ‘by the petitioner’ at the litigation’s 

end.” Ante, at 9–10. But weeded-out challenges are the

same as settled matters and canceled claims in this respect. The petitioner cannot continue to challenge a claim

once that challenge is weeded out by the Board at the 

institution phase. He cannot pursue it before the Board in

the inter partes review, and normally he cannot pursue it 

in a court of appeals. See Cuozzo, 579 U. S., at ___–___ 

(slip op., at 11–12). The petitioner might bring a totally 

separate case in court in which he challenges the claim,

but that is a different matter that is not the subject of this

statutory chapter.

Nor does the chapter’s structure help fill the statutory 

gap. I concede that if we examine the “final written decision” section, §318(a), just after reading the three initial 

sections of the statute, §§311, 312, and 313, we may be 

tempted to believe that the words “any patent claim challenged” in §318(a) must refer to the claims challenged in 

the petition, just as the words “each claim challenged” in

§312(a)(3) unmistakably do. But once we look at the 

whole statute, this temptation disappears. The first section, §311, describing the inter partes review process, does

not use the word “challenge.” The next section, §312,

describes the requirements for the initial petition, which is 
 

 

 

 

6 SAS INSTITUTE INC. v. IANCU 

BREYER, J., dissenting 

filed before any inter partes proceeding has been instituted. It is about the petition, so it is not surprising that it

refers to the claims challenged in the petition. The next 

section, §313, concerns the preliminary response, which is 

similarly filed before the inter partes review proceeding

has been instituted and is thus similarly focused on the 

petition, although it does not use the word “challenged.” 

The very next section, however, §314, along with part of

§315, describes preliminary screening and the institution 

of the inter partes review proceeding. The remainder of 

§315, and the following sections, §§316 and 317, then

describe how that proceeding, once instituted, will be 

conducted (and provide for settlements). Only then does 

§318 appear. That statutory provision tells the Board 

that, at the conclusion of the inter partes review proceeding, it must “issue a final written decision with respect to

the patentability of any patent claim challenged by the

petitioner.” §318(a). And in this context, a context about 

the inter partes review proceeding itself, it is more than 

reasonable to think that the phrase “patent claim challenged by the petitioner” refers to challenges made in the

proceeding, not challenges made in the petition but never 

made a part of the proceeding.

I am not helped by examining, as the majority examines, what Congress might have done had it used other 

language. Ante, at 6–8. The majority points out that had 

Congress meant anything other than “challenged in the 

petition,” it might have said so more clearly. Ibid. But 

similarly, if Congress had meant “challenged in the petition,” it might have used the words “in the petition.” After 

all, it used those very words only four sections earlier. See 

§314(a) (referring to “claims challenged in the petition”).

This argument, like many such arguments, is a wash. 

Neither am I helped by analogizing the inter partes

review proceeding to civil litigation. Cf. ante, at 2–3, 5. 

That is because, as this Court said in Cuozzo, inter partes 
Cite as: 584 U. S. ____ (2018) 7 

BREYER, J., dissenting 

review is a “hybrid proceeding.” 579 U. S., at ___ (slip op., 

at 16). It has some adversarial characteristics, but “in 

other significant respects, inter partes review is less like a 

judicial proceeding and more like a specialized agency 

proceeding.” Id., at ___ (slip op., at 15). Its purposes are

not limited to “helping resolve concrete patent-related 

disputes among parties,” but extend to “reexamin[ing] . . . 

an earlier administrative grant of a patent” and “protect[ing] the public’s ‘paramount interest in seeing that 

patent monopolies . . . are kept within their legitimate

scope.’” Ibid. (quoting Precision Instrument Mfg. Co. v. 

Automotive Maintenance Machinery Co., 324 U. S. 806, 

816 (1945); ellipsis in original); see also Oil States Energy 

Services, LLC v. Greene’s Energy Group, LLC, ___ U. S. 

___, ___–___ (2018) (slip op., at 8–9). 

Finally, I would turn to the likely purposes of the statutory provision. As the majority points out, §314(a) makes 

clear that the “Director” (now his delegate, the Board) is to

determine whether there is a “reasonable likelihood” of 

success as to at least one of the claims the petition challenges. If not, he cannot initiate an inter partes review 

proceeding. If so, §314(a) “invests the Director with discretion on the question whether to institute review.” Ante, 

at 8 (emphasis deleted); Cuozzo, supra, at ___ (slip op., at 

9). As I have said, Patent Office regulations allow the 

Board to proceed with inter partes review of some of the 

claims a petitioner challenges (say, only those where there 

is a reasonable likelihood of success), but not of others. 37 

CFR §42.108(a).

The majority points out that it does not follow from

§314(a) that the statute affords the Director discretion

regarding what claims that review will encompass. The 

text says only that the Director can decide “whether” to

institute the requested review, not “whether and to what 

extent” review should proceed. Ante, at 8 (emphasis deleted). That is certainly so. But I think that when we, as 
 

 

8 SAS INSTITUTE INC. v. IANCU 

BREYER, J., dissenting 

judges, face a difficult text, it is often helpful to ask not 

just “whether” or “what” but also “why.” Why, asks the

Patent Office, would Congress have intended to require 

the Board to proceed with an inter partes review, take 

evidence, and hear argument in respect to challenges to

claims that the Board had previously determined had no

“reasonable likelihood” of success? The statute would 

seem to give the Director discretion to achieve the opposite, namely, to avoid wasting the Board’s time and effort 

reviewing challenges that it has already decided have no 

“reasonable likelihood of success.” In my example, why

make the Board do further work on the challenges to 

claims 1 through 15, which the Board has already decided

are near frivolous? 

More than that, to read §318(a) as requiring a “final

written decision” in respect to those 15 perhaps frivolous

challenges would seem to lead to judicial review of the 

Board’s decision about those frivolous challenges. After 

all, §319 of the statute says that a “party dissatisfied with 

the final written decision of the [Board] under section 

318(a),” the provision before us, “may appeal the decision”

to the Federal Circuit. And the majority’s interpretation 

is anomalous in that it is difficult to imagine why Congress, with one hand, would make the agency’s weedingout decision nonreviewable, see Cuozzo, supra, at ___–___ 

(slip op., at 11–12), yet at the same time would make the

decision reviewable via the requirement that the Board 

issue a “final written” appealable “decision” with respect 

to that weeded-out challenge. 

III 

I end up where I began. Section 318(a) contains a gap 

just after the words “challenged by the petitioner.” Considerations of context, structure, and purpose do not close 

the gap. And under Chevron, “where a statute leaves a 

‘gap’ or is ‘ambigu[ous],’ we typically interpret it as grant-
Cite as: 584 U. S. ____ (2018) 9 

BREYER, J., dissenting 

ing the agency leeway to enact rules that are reasonable in 

light of the text, nature, and purpose of the statute.” 

Cuozzo, supra, at ___ (slip op., at 13) (quoting United 

States v. Mead Corp., 533 U. S. 218, 229 (2001); alteration 

in original). 

A 

In referring to Chevron, I do not mean that courts are to 

treat that case like a rigid, black-letter rule of law, instructing them always to allow agencies leeway to fill

every gap in every statutory provision. See Mead Corp., 

supra, at 229–231. Rather, I understand Chevron as a 

rule of thumb, guiding courts in an effort to respect that

leeway which Congress intended the agencies to have. I 

recognize that Congress does not always consider such

matters, but if not, courts can often implement a more 

general, virtually omnipresent congressional purpose—

namely, the creation of a well-functioning statutory

scheme—by using a canon-like, judicially created construct, the hypothetical reasonable legislator, and asking 

what such legislators would likely have intended had 

Congress considered the question of delegating gap-filling 

authority to the agency. 

B 

To answer this question, we have previously held that a

“statute’s complexity, the vast number of claims that it 

engenders, and the consequent need for agency expertise 

and administrative experience” normally “lead us to read 

[a] statute as delegating to the Agency considerable authority to fill in, through interpretation, matters of detail

related to its administration.” Barnhart v. Walton, 535 

U. S. 212, 225 (2002). These considerations all favor such 

a reading here. Indeed, the question before us is one of 

agency administration in respect to detailed matters that

an agency working with the statute is particularly likely 
 

 

10 SAS INSTITUTE INC. v. IANCU 

BREYER, J., dissenting 

to understand. In addition, the agency filled the gap here

through the exercise of rulemaking authority explicitly

given it by Congress to issue regulations “setting forth the 

standards for the showing of sufficient grounds to institute

a review” and “establishing and governing inter partes

review.” §§316(a)(2), (4); Cuozzo, 579 U. S., at ___–___ 

(slip op., at 12–13); cf. Mead Corp., supra, at 227. Thus, 

there is a gap, the agency possesses gap-filling authority,

and it filled the gap with a regulation that, for reasons I 

have stated, is a reasonable exercise of that authority. 

* * * 

I consequently would affirm the judgment of the Federal

Circuit. And, with respect, I dissent from the Court’s 

contrary conclusion.