Patents

SAS Institute v. Iancu: The End of Partial Institution at the PTAB

The Supreme Court held that when the Patent Office institutes an inter partes review, it must decide the patentability of every claim the petitioner challenged — all or nothing.

May 19, 2025
A close-up of a statute book open to text with a pen resting on the page
The Court read a single word — 'any' — in Section 318(a) to require the Board to rule on all challenged claims. Shutterstock
Educational content, not legal advice. This article explains general legal concepts. It does not create an attorney–client relationship. For your specific situation, consult a licensed attorney.

SAS Institute Inc. v. Iancu, No. 16-969 (U.S. Apr. 24, 2018), dismantled one of the Patent Trial and Appeal Board’s most efficiency-minded habits: the practice of “partial institution,” under which the Board would agree to review some of the patent claims a petitioner challenged while declining to touch the rest. By a 5-4 vote, in an opinion by Justice Gorsuch, the Supreme Court held that the inter partes review statute admits no such picking and choosing. When the Patent Office institutes a review, it must issue a final written decision addressing the patentability of every claim the petitioner has challenged. The ruling, handed down the same day as Oil States, left IPR constitutionally secure but procedurally transformed.

At a glance

  • Case: SAS Institute Inc. v. Iancu, No. 16-969
  • Court: Supreme Court of the United States
  • Decided: April 24, 2018
  • Vote: 5-4; majority by Justice Gorsuch (joined by Chief Justice Roberts and Justices Kennedy, Thomas, and Alito); dissents by Justices Ginsburg and Breyer
  • Statute construed: 35 U.S.C. § 318(a), the final-written-decision provision of inter partes review
  • Regulation invalidated: The PTO’s partial-institution practice (then reflected in 37 C.F.R. § 42.108(a))
  • Holding: When the Director institutes an IPR, the Board must address the patentability of all claims the petitioner challenged, not a subset
  • Disposition: Reversed and remanded

The facts: nine of sixteen

SAS Institute filed a petition for inter partes review challenging all 16 claims of a software patent owned by ComplementSoft. The Director — acting through the Board — instituted review on only nine of those 16 claims and denied review on the remaining seven. The Board then issued a final written decision addressing only the nine instituted claims, saying nothing about the other seven. SAS objected: the statute, it argued, required a final decision on every claim it had challenged, not just the ones the Board found worth examining.

The Federal Circuit rejected the argument, relying on the agency’s longstanding partial-institution regulation. SAS took the question to the Supreme Court, which granted certiorari and reversed.

The text: “any” means every

The majority’s reasoning is a compact exercise in statutory construction. Section 318(a) provides that “[i]f 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.” Justice Gorsuch fixed on three features of that sentence.

First, the word “shall” imposes a nondiscretionary duty: the Board must issue the decision. Second, the phrase “any patent claim challenged by the petitioner” defines the scope of that decision by reference to the petitioner’s challenge, not the Director’s institution choices. In this context, the majority held, “any” carries an expansive, all-encompassing meaning — the Board must address every claim the petitioner challenged. Third, the statute speaks of claims “challenged by the petitioner,” not claims the Board elected to review, confirming that the petitioner — not the agency — sets the agenda for what the final decision must resolve.

The Court reinforced the point with the statute’s design. Throughout the IPR provisions, Congress framed the proceeding around the petition. The petitioner, not the Director, defines the claims and grounds; the statute repeatedly returns to “the petitioner” as the lodestar. That structure, the majority said, is “a party-directed, adversarial process,” not an “inquisitorial” one in which the agency roams as it pleases. Allowing the Board to carve up a petition and answer only part of it was inconsistent with that design.

The institution decision: binary, not granular

Central to the holding is the Court’s reading of the institution decision itself. Under 35 U.S.C. § 314, the Director decides whether to institute based on whether there is “a reasonable likelihood that the petitioner would prevail with respect to at least 1 of the claims challenged.” The majority seized on “at least 1”: Congress made institution turn on a single qualifying claim, which signals that institution is an all-or-nothing gateway. Once that threshold is crossed for any claim, the proceeding is instituted as to the petition — and the final decision must then reach the whole of what the petitioner challenged.

The Director argued that § 314’s grant of discretion over whether to institute implies discretion over what to institute, including the power to institute on a claim-by-claim basis. The Court rejected the inference. The statute gives the Director discretion only over the binary choice to institute or not; it says nothing authorizing a partial institution. And because the question was answered by the statute’s text, the agency was not entitled to Chevron deference: there was no ambiguity to fill.

The dissents pressed the practical and administrative case. Justice Ginsburg’s brief dissent suggested the agency could achieve much the same efficiency by other means — for instance, by denying weak petitions and inviting refiled petitions limited to the stronger claims. Justice Breyer’s dissent, joined in part by others, argued that the statute left a gap that the agency reasonably filled, and that the majority’s reading would force the Board to adjudicate claims it had already judged unlikely to fall.

Open questions

SAS answered the claim-scope question cleanly but unsettled the grounds question and several downstream issues. The opinion held that institution must cover all challenged claims; it did not squarely decide whether the Board must also address every ground of unpatentability asserted against those claims. The PTO read SAS to require all-grounds institution as a matter of practice, but the statutory command in the opinion is framed in terms of claims. The decision also reshaped the timing and scope of IPR estoppel under § 315(e), because estoppel attaches to claims that reach a final written decision — and after SAS, that universe expanded. Finally, SAS left the Director’s broad discretion to deny institution untouched, which in later years became the fulcrum for discretionary-denial policies that effectively restored some agency control over which disputes proceed.

Implications

  • No more partial institution. The Board must take the petition whole or not at all; it cannot trim a challenge down to its strongest claims at the institution stage.
  • Estoppel exposure grew. Because final written decisions now cover every challenged claim, the estoppel that follows under § 315(e) reaches further, raising the stakes of filing an IPR for both petitioners and patent owners.
  • Institution discretion shifted, not vanished. The Director lost the ability to institute partially but retained wide latitude to deny institution entirely — discretion later exercised aggressively through denial frameworks.
  • Petitioners must build complete petitions. With all-or-nothing institution, weak claims included in a petition can dilute the whole; petition drafting became a higher-stakes triage exercise.
  • Same day, different lever. Paired with Oil States, SAS shows the 2018 Court securing IPR’s existence while tightening the statutory rules that govern how the Board must run it.

Frequently asked questions

Did SAS Institute require the Board to address every ground of unpatentability, or just every claim? The holding is phrased in terms of claims: institution must reach all claims the petitioner challenged. The PTO subsequently applied the decision to require all-grounds institution as a matter of practice, but that practice flows from the agency’s reading of SAS rather than from an explicit statement that grounds, as opposed to claims, are constitutionally or statutorily required.

Does SAS mean the Patent Office must institute review whenever a petition is filed? No. The Director retains full discretion to deny institution. SAS governs only what happens after institution: once the Director institutes, the final written decision must cover all challenged claims. The agency can still decline to institute at all, including for discretionary reasons.

How did SAS change estoppel? IPR estoppel under § 315(e) attaches to claims that reach a final written decision. By forcing final decisions to cover every challenged claim, SAS enlarged the set of claims to which estoppel applies, meaning a petitioner can be barred from later raising invalidity arguments it raised or reasonably could have raised as to all of those claims.

Authorities and sources