Background
CAO Lighting, a manufacturer of high-brightness LED technology, challenged the validity of several Wolfspeed patents through inter partes review (IPR) proceedings at the Patent Trial and Appeal Board. The PTAB ruled against CAO Lighting, and the company appealed to the Federal Circuit. The appeals court disposed of the case with a one-line Rule 36 judgment — affirming the PTAB’s decisions without issuing any written opinion or reasoning.
CAO Lighting then petitioned the Supreme Court, mounting a novel constitutional challenge to Rule 36 practice. The petition argued that the Supreme Court’s landmark 2024 decision in Loper Bright Enterprises v. Raimondo — which held that courts must exercise “independent judgment” when reviewing agency action — fundamentally undermines the Federal Circuit’s practice of rubber-stamping PTAB decisions without explanation. Under 28 U.S.C. § 144 and the Administrative Procedure Act, CAO Lighting contended, courts are required to issue an “opinion” when reviewing agency decisions, not a bare affirmance.
This petition was the latest in a series of challenges to Rule 36 at the Supreme Court. CPC Patent Technologies’ petition (No. 25-1104) was denied just weeks earlier in April 2026, and ParkerVision’s petition had been denied before that. Statistical analyses have shown that the Federal Circuit issues Rule 36 summary affirmances in approximately 43% of PTAB appeals — a rate that critics argue deprives patent owners of meaningful judicial review.
The Court’s Holding
The Supreme Court denied the petition for certiorari without comment. No Justice publicly dissented or issued a statement regarding the denial. The denial leaves the Federal Circuit’s Rule 36 practice intact and its summary affirmance of the PTAB decisions in CAO Lighting’s cases undisturbed.
By declining review, the Court signaled — at least for now — that it does not view the tension between Loper Bright’s “independent judgment” mandate and Rule 36’s no-opinion dispositions as warranting its intervention. The denial comes despite mounting criticism from patent practitioners, academics, and even former Federal Circuit judges who have questioned whether summary affirmances provide adequate appellate review of PTAB proceedings.
Key Takeaways
- Rule 36 survives another Supreme Court challenge. This is at least the fourth cert petition challenging the Federal Circuit’s summary affirmance practice to be denied in recent years, signaling that the Court is unlikely to intervene through this avenue.
- Loper Bright’s reach has limits. The denial suggests the Court does not view Loper Bright’s mandate for independent judicial review of agency action as extending to the form in which appellate courts issue their decisions.
- PTAB appellants face an uphill battle. With 43% of PTAB appeals resolved by Rule 36, patent owners who lose at the Board may receive no written explanation for why the Federal Circuit affirmed — making it difficult to identify errors or seek further review.
Why It Matters
The Rule 36 debate touches a nerve in patent practice because it sits at the intersection of administrative law, patent rights, and due process. For patent owners who invest years and significant resources in IPR proceedings, a one-line affirmance with no reasoning can feel like a denial of justice. For the Federal Circuit, which faces a heavy docket of PTAB appeals, Rule 36 is an essential case-management tool.
The Supreme Court’s repeated refusal to engage with this issue effectively leaves reform to Congress or the Federal Circuit itself. Legislative proposals to require written opinions in PTAB appeals have been introduced but have not advanced. Until something changes, patent owners appealing PTAB decisions should be prepared for the possibility that their appeals will be decided without any explanation — and should focus their advocacy on making the strongest possible record at the Board level.