USPTO Tightens “Unintentional Delay” Petitions — 1-Year Time Period Now Triggers Heightened Scrutiny

For publication in the Federal Register of June 24, 2026, having an effective of August 13, 2026, the USPTO is issuing a final rule to significantly tighten its review of petitions based on “unintentional delay.” For petitions filed on or after August 13, 2026, the USPTO will require additional evidentiary support—and impose higher fees—for petitions filed more than one year after a missed deadline, replacing the prior two-year threshold.

The USPTO explains the policy rationale behind the rule change. The Final Rule is intended to:

• Increase certainty and predictability of patent rights
• Reduce disruption to third parties who may rely on:
• Abandoned applications
• Expired patents
• Missing priority claims
• Ensure that only delays that are genuinely “unintentional” result in revival or reinstatement

Key Changes

1. Reduced Time Period for Heightened Scrutiny

The USPTO has shortened the period after which it will question whether a delay was truly “unintentional”:

• Old rule: Additional information required if delay > 2 years
• New rule: Additional information required if delay > 1 year

This applies to petitions involving:

• Revival of abandoned applications and reexamination proceedings under 37 C.F.R. § 1.137
• Acceptance of delayed maintenance fee payments under 37 C.F.R. § 1.378
• Delayed priority or benefit claims under 37 C.F.R. §§ 1.55(e) and 1.78(c) or (e)
• Missed deadlines in international design applications under 37 C.F.R. § 1.1051

2. Expanded Evidentiary Requirements

For petitions filed more than one year after the relevant deadline, applicants must now:

• Provide a detailed explanation of the entire period of delay
• Demonstrate that the delay was unintentional in fact, not merely assert it

The USPTO continues to accept applicant certifications in routine cases, but views longer delays as inherently raising doubt about intent.

3. Earlier Trigger for Higher Petition Fees

The rule also revises the fee structure:

• The higher petition fee under 37 CFR 1.17(m)(1) now applies when a petition is filed more than one year after the missed action
• Previously, this fee applied only after two years

This change reinforces the USPTO’s objective of encouraging prompt corrective filings.

4. No Safe Harbor Below One Year

Importantly, the one-year threshold is not a safe harbor:

• The USPTO retains discretion to require additional information at any time where it questions whether a delay was unintentional