Statutory Patent Disclaimers

Statutory disclaimer

Under 35 U.S.C. § 253(a), a patent owner may disclaim any complete claim. The disclaimer is filed with a fee and is recorded in the patent file. It is irrevocable: a disclaimed claim cannot later be asserted.

Owners use statutory disclaimers to:

• drop a claim found invalid or unneeded, which can reduce exposure in litigation;
• remove a claim that may be anticipated by newly discovered art;
• narrow the patent in response to a challenge.

Terminal disclaimer

Under § 253(b), an owner may disclaim or dedicate to the public any terminal part of the patent’s term. The most common use is to overcome obviousness-type double patenting between related patents. A terminal disclaimer typically requires that the patents remain commonly owned for as long as they are enforceable, so it can limit later transfers.

Practical effects

• A terminal disclaimer shortens, or aligns, the term of the later patent with the earlier one.
• Disclaimers do not remove the need to address other invalidity grounds.
• A disclaimer after a challenge begins can affect proceedings in different ways, so ask a practitioner before filing during a dispute.

If errors, not claim scope, are the problem, consider reissue or a certificate of correction.