For high-value patents, a single month of extra term can translate into significant back-end revenue. But maximizing the enforceable life of a patent depends on the precise verification of USPTO Patent Term Adjustment (PTA) — a statutory calculation that the USPTO frequently gets wrong.
PTA is intended to compensate patentees when examinations and issuances are delayed by the USPTO. The statutory framework, in 35 U.S.C. § 154(b), turns a prosecution timeline into extra terms that can span hundreds of days.1
USPTO PTA is not a simple equation. It depends on the correct capture of dozens of prosecution events that can be reduced by overlap and applicant delay and is a composite of A-delay, B-delay, and C-delay.
Why Do USPTO PTA Mistakes Matter More than Ever?
For commercial portfolios, PTA can translate into significant revenue. Additional back-end exclusivity can affect licensing negotiations, enforcement leverage, and competitive timing.
Also, the correction window for PTA is short. A request for reconsideration must be filed within two months of the patent grant date, and extensions are only available up to seven months from the grant.2
Further, USPTO PTA has become the norm, not the exception. A study of about 4.5 million U.S. patents found that 63.7% received at least some PTA, with a mean of 262 days. The mean rose to 411 days when the focus was narrowed to look at patents that received PTA specifically.3
When a USPTO PTA number is wrong and no one challenges it within the correction window, the loss becomes irreversible.
What Does the Record Show About PTA Calculation Risk?
A 2021 evaluation commissioned by the Department of Commerce’s Office of Inspector General (performed by MITRE) underscores why independent verification is a best practice.
According to the evaluation, 92% of the USPTO PTA calculator’s reviewed software requirements were fully compliant with relevant statutes, regulations, and case law. A meaningful remainder, however, were not fully compliant — often due to missing details such as complete event-code lists.
The evaluation also noted that system requirements had not been updated since 2015 and that competing IT funding priorities contributed to a growing backlog of needed updates.4
Separately, PTA doctrine has been shaped by Federal Circuit decisions interpreting how to compute A-delay, B-delay, overlap, and applicant delay. When doctrine moves, guidance and systems must move with it — often after an implementation lag.5
The Deadline Problem: Seven Months Can Disappear Fast
The reconsideration mechanism is procedural and unforgiving. Under 37 C.F.R. § 1.705(b), a
request for reconsideration of PTA indicated on the patent must be filed within two months of grant (with extensions under 37 C.F.R. § 1.136(a), but never beyond seven months from grant).
The lack of deadline flexibility even includes problems created and acknowledged by the USPTO.
For example, the USPTO published an Official Gazette notice on September 25, 2024, disclosing that a software update introduced a coding error into its USPTO PTA calculation program.
The Office stated the error affected certain patents issued from March 19, 2024, through July 30, 2024, potentially miscalculating A-delay and overlap, and estimated that approximately 1% of patents issued in that window may have been impacted.6
In its September 2024 coding-error notice, the USPTO emphasized that it would not consider untimely requests and would not grant petitions to extend that deadline.2,6
Critically, the USPTO did not publish a list of affected patent numbers. Patent owners and counsel had to self-identify discrepancies and file timely requests for reconsideration.
The USPTO waived the petition fee (and extension fees) where the sole basis for the request
was the disclosed A-delay/overlap coding error. Outside that narrow scenario, however, fees still applied, and the burden remained on the patent owner to detect problems and take action.6,9
A Practical Checklist for Firms
Many firms treat PTA verification as an issuance-day control, not a one-off spot check. The minimum steps to reduce portfolio-wide risk are:
- Capture the PTA determination and the underlying prosecution timeline immediately upon issuance.
- Recompute PTA (A, B, C, applicant delay, and overlap) independently from the file history and compare to the patent’s face value.
- Assess whether discrepancies are petitionable issues and prepare timely requests for reconsideration under the USPTO’s petition process.
- File well before the outer deadline; internal drafting and filing logistics can consume the window faster than expected.8,7
Automated Verification and Signature-Ready Petitions
Black Hills AI’s PTA Verification service is specifically designed for these short filing windows and hard-to-find errors.
When a patent is granted, our system automatically performs an independent rule-based calculation based on the prosecution history within the Pipeline™ platform and flags discrepancies against the USPTO’s published PTA.
When the system finds a discrepancy, Black Hills AI produces a signature-ready filing package that includes the reconsideration request and supporting calculations. Rather than starting from a blank page, your practitioner reviews, signs, and files a pre-built package.
For teams that prefer a managed workflow, Black Hills AI can also assist with filing logistics after signature so submissions are made quickly within the statutory window.
In simple terms, connecting your portfolio to the Pipeline™ platform results in fewer missed PTA corrections, a greatly reduced need for internal drafting, and a defensible, repeatable issuance-day control for patent owners.
Try PTA Verification for Free
If you’d like to see how often PTA discrepancies appear in your own grants, Black Hills AI is
offering free PTA verification for up to five recently granted patents — including signature-ready petitions for any discrepancies identified.
Visit blackhills.ai or contact the Black Hills AI team to get started.
Citations
135 U.S.C. § 154(b) (2024).
237 C.F.R. § 1.705(b) (2025); 37 C.F.R. § 1.136(a) (2025). See also U.S. Patent & Trademark Off., Coding Error Impacting USPTO Patent Term Adjustment Software 2 (Off. Gaz. Pat. Off., Sept. 25, 2024), https://www.uspto.gov/sites/default/files/documents/og-pta-software-error.pdf (stating untimely requests will not be considered and no petitions under 37 C.F.R. §§ 1.182 or 1.183 will extend the deadline).
3Mark A. Lemley & Jason Reinecke, Our More-than-Twenty-Year Patent Term, 39 Berkeley Tech. L.J. 681, 693-94 (2024).
4U.S. Dep’t. of Com., Off. of Inspector Gen., USPTO Has Opportunities to Improve Its Internal Controls and Oversight Related to PTA and PTE Calculations, Final Report No. OIG-21-030-I, at 15 (July 6, 2021), https://www.oig.doc.gov/wp-content/OIGPublications/OIG-21-030-I.pdf.
5See, e.g., Wyeth v. Kappos, 591 F.3d 1364 (Fed. Cir. 2010); Novartis AG v. Lee, 740 F.3d 593 (Fed. Cir. 2014); Supernus Pharms., Inc. v. Iancu, 913 F.3d 1351 (Fed. Cir. 2019).
6U.S. Patent & Trademark Off., Coding Error Impacting USPTO Patent Term Adjustment Software 1-2 (Off. Gaz. Pat. Off., Sept. 25, 2024), https://www.uspto.gov/sites/default/files/documents/og-pta-software-error.pdf.
7Manual of Patent Examining Procedure § 2734 (U.S. Pat. & Trademark Off. [R-01.2024]), https://www.uspto.gov/web/offices/pac/mpep/s2734.html.
8U.S. Pat. & Trademark Off., Petition Requesting Reconsideration of the Patent Term Adjustment After Issuance of the Patent (Oct. 1, 2018), https://www.uspto.gov/patents/apply/petitions/30-petition-requesting-reconsideration-patent-term-adjustment.
937 C.F.R. § 1.18(e) (2025).