# Patent term

The length of time a patent stays in force. A U.S. utility patent's term runs 20 years from its earliest non-provisional filing date, provided maintenance fees are paid; a design patent lasts 15 years from grant. Patent Term Adjustment can add back days lost to USPTO delays, and a terminal disclaimer can shorten the term. When the term ends, the invention enters the public domain.

**Full entry:** https://patentbrief.org/glossary/patent-term

**All patent terms:** https://patentbrief.org/glossary

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_Source: PatentBrief — https://patentbrief.org. A plain-English glossary of US patent terms._