Patent bar Patent term, adjustment, extension and maintenance fees question: Hana Kimura filed an international application under the PCT on Monday

Patent barPatent term, adjustment, extension and maintenance fees

Hana Kimura filed an international application under the PCT on Monday, February 10, 2025, claiming priority to a Japanese application filed Monday, February 12, 2024. The national stage in the United States commenced on Wednesday, August 12, 2026. Ignoring adjustment and extension, when will the U.S. patent expire?

A February 10, 2045, because the term runs from the PCT filing date
B August 12, 2044, twenty years from the thirty-month national stage date
C Seventeen years from the date on which the U.S. patent is granted
D August 12, 2046, twenty years from the start of the national stage
E February 12, 2044, twenty years from the Japanese priority date

Show the answer and explanation

Answer: A. February 10, 2045, because the term runs from the PCT filing date

Answer: February 10, 2045, because the term runs from the PCT filing date. A patent granted on an international application that enters the national stage under 35 U.S.C. 371 has a term ending 20 years from the international filing date (MPEP 2701, subsection II). Priority under 35 U.S.C. 119 and 365(b) is not considered (35 U.S.C. 154(a)(3)). Why not the others: - The Japanese date: foreign priority is excluded from the term. - The national stage date: national stage commencement matters for PTA (14-month and three-year clocks), not for the 20-year term. - Thirty months from priority: that is roughly when the national stage is due; it is not a term date. - Seventeen years from grant applies only to pre-June 8, 1995 filings. Rule: A U.S. patent from a PCT national stage expires 20 years from the international filing date. Source: MPEP § 2701 (9th ed., Rev. 01.2024); 35 U.S.C. 154(a)(2), 154(a)(3), 363; as at Oct 2026

Common mistake

Running the term from national stage entry because that is when the U.S. case begins.

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Original study material written from the MPEP; not a question from the current exam.Independent. Not affiliated with or endorsed by the USPTO. Verify figures and rules against current guidance before relying on them.