For modern U.S. utility and plant patents, the general term is twenty years measured from the relevant filing date. That date may be an earlier non-provisional filing in the application chain. The term is not ordinarily twenty years from the grant date.
The General Rule Has Qualifications
Patent term adjustment, patent term extension, terminal disclaimers, and older filing rules can change the calculation. A cover-page date alone is not enough to establish when a particular patent expires.
Design patents based on applications filed on or after May 13, 2015 generally have a fifteen-year term from grant. Earlier design applications follow a different rule.
Maintenance Fees Matter
U.S. utility patents generally require maintenance fees at 3½, 7½, and 11½ years after grant. Failure to pay can cause expiration, subject to applicable grace periods and possible procedures for accepting a late payment. Design and plant patents do not require these maintenance fees.
Check the Record
Review the application history, disclaimers, adjustments, and fee record before relying on a term calculation. The USPTO’s maintenance tools provide official payment information. Our cost guide explains why filing fees are only part of a patent budget.