How long does a patent last?

Patent terms at a glance

US utility patents: 20 years from which date?

Under 35 U.S.C. 154(a)(2), the term starts when the patent issues and ends 20 years from the date the US application was filed. If the application claims the benefit of an earlier US nonprovisional or international application (as a continuation, divisional or continuation-in-part under sections 120, 121, 365(c) or 386(c)), the 20 years run from the earliest of those. Priority from a foreign application, and the benefit of a provisional, are not taken into account (154(a)(3); MPEP 2701).

• Provisional first. A provisional filed March 2, 2026, then a nonprovisional on March 1, 2027: the patent runs to March 1, 2047, almost 21 years after the first filing.
• Continuation. A continuation filed in 2030 from a 2026 parent expires 20 years from the parent's 2026 filing date, like the parent, not 2050.
• Foreign priority. A US application filed June 10, 2026 claiming priority from a German application of June 12, 2025 runs to June 10, 2046.
• PCT national stage. The 20 years run from the international filing date, because the US national stage relies on the international application.

Older patents follow a transition rule. A patent in force on June 8, 1995, or issued on an application filed before that date, lasts the longer of 20 years from filing or 17 years from grant (154(c)(1); MPEP 2701). Few of these remain in force, but they still turn up in litigation and in long-pending applications.

Design and plant patents

A design patent lasts 15 years from the date of grant if the application was filed on or after May 13, 2015, and 14 years from grant if filed before (35 U.S.C. 173; MPEP 2701). Because the clock starts at grant, a slow examination does not cost design term. Plant patents follow the utility rules, 20 years from filing, through 35 U.S.C. 161. Neither pays maintenance fees (35 U.S.C. 41(b)(3)).

Patent term adjustment (PTA)

Because the 20 years run during examination, Congress gave back time lost to USPTO delay. 35 U.S.C. 154(b) adds one day of term for each day of three kinds of delay:

Three limits apply (154(b)(2)). Where A, B and C periods overlap, a day is counted only once, so the total cannot be more than the actual number of days issuance was delayed. Days of applicant delay are subtracted; taking more than 3 months to reply to an office action counts as applicant delay day for day, even with a paid extension, and the USPTO's rules in 37 CFR 1.704 list other conduct that reduces PTA. And a patent subject to a terminal disclaimer cannot be adjusted past the disclaimed date.

Example. An application filed January 10, 2022 gets its first action 18 months later (4 months of A delay) and is granted on July 10, 2025 (6 months of B delay). The A delay fell within the first 3 years, so it does not overlap the B period, and the applicant took one extra month to reply once (1 month of applicant delay). Net PTA is roughly 9 months, so the patent expires around October 2042 instead of January 10, 2042.

The USPTO calculates PTA and prints it on the patent. If you think it is wrong, a request for reconsideration is due within 2 months of grant, extendable under 37 CFR 1.136(a) (37 CFR 1.705(b)). After the Director's decision, a civil action must be brought in the Eastern District of Virginia within 180 days (154(b)(4)(A)).

Patent term extension (PTE) for regulated products

Drugs, biologics, medical devices and some food and color additives cannot be sold until a regulator approves them, which eats into the term. 35 U.S.C. 156 lets the owner extend one patent for the product:

• the application must be filed within 60 days of the approval (156(d)(1));
• the extension cannot exceed 5 years (156(g)(6)(A)), and the remaining term after approval plus the extension cannot exceed 14 years (156(c)(3));
• a patent can be extended only once, and only one patent can be extended for the same regulatory review period (156(a)(2), (c)(4)).

The USPTO application fee is $2,500, with no entity discount (37 CFR 1.20(j)).

Terminal disclaimers and double patenting

When two of your own patents or applications claim inventions that are not patentably distinct, the examiner issues a nonstatutory (obviousness-type) double patenting rejection. The usual answer is a terminal disclaimer: you give up any term of the later patent that extends past the earlier one. Under 37 CFR 1.321(c), the disclaimer must also make the patent enforceable only while it is commonly owned with the reference patent. The filing fee is $183 for every entity size.

PTA interacts with this. In In re Cellect (Fed. Cir. August 28, 2023; certiorari denied October 7, 2024), the court held that double patenting must be judged on the expiry date after PTA is added. A family member that earned PTA can therefore be invalid for double patenting over a sibling that expires earlier, unless a terminal disclaimer was filed in time. PTE is treated differently: the comparison uses the date before the extension. The USPTO proposed a rule in 2024 that would have tied terminal disclaimers to enforceability more broadly, then withdrew it on December 4, 2024 (89 FR 96152).

Maintenance fees: the way most patents end early

A utility patent stays in force only if three maintenance fees are paid (35 U.S.C. 41(b), 37 CFR 1.362). Each window opens 6 months before the due date; after the due date a 6-month grace period runs, with a surcharge of $540 ($216 small, $108 micro). The times are counted from grant.

If nothing is paid by the end of the grace period, the patent expires at the 4th, 8th or 12th anniversary of grant. The owner can petition to accept the late payment if the delay was unintentional (37 CFR 1.378); the large entity petition fee is $2,260 for a delay of one year or less and $3,000 for a longer delay (37 CFR 1.17(m)). Fee amounts are on USPTO patent fees.

Europe: 20 years, plus SPCs for medicines

A European patent lasts 20 years from the filing date of the application (Article 63(1) EPC), and renewal fees are due every year from the third year, to the EPO while the application is pending and then to each country or, for a Unitary Patent, to the EPO. There is no PTA. For medicinal and plant protection products, a national supplementary protection certificate under Regulation (EC) No 469/2009 runs on after the patent: its length is the time from the patent filing to the first EU marketing authorization, minus 5 years, capped at 5 years (Article 13), with a further 6 months for an agreed pediatric investigation plan (Regulation (EC) No 1901/2006, Article 36). The application is due within 6 months of the authorization, or of grant if that comes later (Article 7). A unitary SPC has been proposed but not adopted. Our guide to supplementary protection certificates covers SPCs in detail, and European costs are in European patent cost.

India: 20 years from filing

An Indian patent lasts 20 years from the filing date, or from the international filing date for a PCT national phase application (Patents Act 1970, section 53); see the Indian patent timeline.

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