A google search reveals that USPTO might mis-calculate the patent term adjustment days.

Do their website they have the right data to allow someone to calculate the patent term-adjustment days or is there data subject to error?

Is the Patent Term Adjustment Days equal to Non-overlapping PTO days minus Applicant Delays?


  • I’m voting to close this question because it belongs on patents.stackexchange.com Oct 20, 2022 at 19:25
  • 1
    This is a question about the application of patent law. It would, I should think, be on-topic at patents.SE. It is also on-top[ic here, and should not be closed. Oct 20, 2022 at 20:38
  • I agree that is on-topic both places. Oct 20, 2022 at 21:59

1 Answer 1


If by "right data" you mean does the record at the USPTO of all the back-and-forth between the applicant and the office reflect what really occurred, then yes.

The linked article says they do not follow the latest ruling on how to use that data to calculate the PTA, not that the data is erroneous. There have been court cases over PTA that the USPTO lost and some they won. If you have a pharmaceutical patent every day is millions of dollars

Then there is a separate thing called Patent Term Extension for regulated inventions.

The calculation is not straightforward see USPTO's explanation of the rules.

(3) "A" DELAYS. This entry reflects adjustments to the term of the patent based upon USPTO delays pursuant to 35 U.S.C. § 154(b)(1)(A)(i)-(iv) and the implementing regulations 37 CFR 1.702(a) & 37 CFR 1.703(a). All "A" delays will be included in the PTA determination that is mailed as part of the ISSUE NOTIFICATION LETTER.

(4) "B" DELAYS. This entry reflects adjustments to the term of the patent based upon the patent failing to issue within three years of the actual filing date of the application in the United States under section 111(a) in the United States or, in the case of an international application, the date of commencement of the national stage under section 371. See 35 U.S.C. § 154(b) and implementing regulations 37 CFR 1.702(b) & 1.703(b). "B" delay is calculated at the time that the issue notification letter is generated and an issue date has been established.

(5) "C" DELAYS. This entry reflects adjustments to the term of the patent based upon USPTO delays pursuant to 35 U.S.C. § 154(C)(i)-(iii) and implementing regulations 37 CFR 1.702 (c)-(e) & 1.703(c)-(e). These delays include delays caused by interference proceedings, secrecy orders, and successful appellate reviews.

(6) OVERLAPPING DAYS BETWEEN "A" AND "B" OR "A" AND "C". This entry reflects the calculation of overlapping delays consistent with the Federal Circuit's interpretation of 35 U.S.C. § 154(b)(2)(A) in Wyeth v. Kappos. Specifically, this entry reflects the summation of the number of days that an "A" delay occurred on the same calendar day with either a "B" delay or a "C" delay. The number of days determined to be overlapping will reduce the summation of the number of days calculated for "A" delays, "B" delays and "C" delays.

(7) NONOVERLAPPING USPTO DELAYS. This entry reflects the overall summation of the USPTO delays minus any overlapping days. Particularly, it includes the following: ("A" delays + "B" delays + "C" delays) - (the number of calendar days overlapping between "A" delays and "B" delay + the number of calendar days overlapping between "A" delays and "C" delays). This entry does not reflect the number of days of applicant delays pursuant to 35 U.S.C. § 154(b)(2)(C) and 37 CFR 1.704(b) and 37 CFR 1.704(c)(1)-(11).

(8) PTO MANUAL ADJUSTMENTS. This entry reflects the UPSTO personnel adjusting the calculation to increase or decrease the patent term adjustment based upon a request for reconsideration of the patent term adjustment pursuant to 37 CFR 1.705(b)

(9) APPLICANT DELAYS. This entry reflects adjustments of the patent term due to the Applicant's failure to engage in reasonable efforts to conclude prosecution of the application for the cumulative period in excess of three months. See 35 U.S.C. § 154(b)(2)(C)(ii) and implementing regulation 37 CFR 1.704(b). The entry also reflects additional Applicant's failure to engage in reasonable efforts to conclude prosecution of the application. See 35 U.S.C. § 154(b)(2)(C)(iii) and implementing regulations 37 CFR 1.704(c)(1)-(12).

(10) TOTAL PTA CALCULATION. This entry reflects the summation of the following entries: NONOVERLAPPING USPTO DELAYS (+/or - PTO MANUAL ADJUSTMENTS) - APPLICANT DELAYS. It is noted that the TOTAL PTA CALCULATION will be determined at the time of the issuance of the patent and will be included in the ISSUE Notification Letter that is mailed to applicants approximately three weeks prior to issuance of the patent.

Note the mention of a court case in (6). The USPTO lost badly in its then (2010) interpretation or PTA rules.

Wyeth v. Kappos- holding that because, in the context of § 154(b)(C), § “154(b)'s language is clear, unambiguous, and intolerant of the PTO's suggested interpretation,” the Federal Circuit “accords no deference to the PTO's [interpretation]

Then there are corner cases and lawsuits - See a quick summary of a case from 2012

In Exelixis, Inc., v. Kappos, the US District Court for the Eastern District of Virginia determined that the US Patent and Trademark Office (USPTO) improperly reduces Patent Term Adjustment (PTA) in patents where the applicant files a Request for Continued Examination (RCE) more than three years after the original patent application filing date. The court held that the USPTO should not deduct any time from an applicant's PTA if the applicant files the RCE more than three years after the patent application was filed.

Outcome Exelixis, Inc., v. Kappos In its November 1, 2012 opinion, the district court agreed with Exelixis and held that Section 154(b)(1)(B) does not require an applicant's PTA to be reduced by the time used to process an RCE that is filed after the end of the three-year application pendency period.

See notes on two cases that went to court from PatentlyO

In Actelion Pharm., Ltd. v. Matal (Fed. Cir. Feb. 6, 2018), the Federal circuit sided with the PTO in a patent term adjustment challenge holding that the PTA calculations beginning with a national-stage application were not triggered by the patentee’s statement that it “earnestly solicits early examination and allowance of these claims.” The problem was that “casual” request was buried within the remarks while the applicant failed to check the box on the form to expressly request.

In a separate recently decided PTA case, a district court has agreed with Ariad that its original RCE filing should only cut-off PTA accumulation since the PTO negligently failed to process the filing (instead sending a notice of abandonment) and then took three months to withdraw the abandonment. ARIAD Pharm., Inc. v. Matal, 1:17-CV-733, 2018 WL 339141, at *1 (E.D. Va. Jan. 5, 2018)

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