What are patent term extensions and adjustments?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

Patent term extensions and adjustments are mechanisms to extend the term of a patent beyond the standard 20-year period. There are two main types:

1. Patent term adjustments under 35 U.S.C. 154 for delays within the USPTO. These apply to utility and plant patents issuing from applications filed on or after June 8, 1995.
2. Patent term extensions under 35 U.S.C. 156 for premarket regulatory review.

The MPEP notes, The patent term extension that may be available under 35 U.S.C. 156 for premarket regulatory review is separate from and will be added to any extension that may be available under former and current 35 U.S.C. 154. For detailed information, refer to MPEP § 2710 et seq. for adjustments and MPEP § 2750 et seq. for extensions.