How does the identification of a single inoperative embodiment affect claim enablement?

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.

The identification of a single inoperative embodiment among many operable embodiments does not necessarily render a claim broader than the enabled scope. The MPEP 2164.08(b) references the In re Angstadt case:

“A disclosure of a large number of operable embodiments and the identification of a single inoperative embodiment did not render a claim broader than the enabled scope because undue experimentation was not involved in determining those embodiments that were operable. In re Angstadt, 537 F.2d 498, 502-503, 190 USPQ 214, 218 (CCPA 1976).”

This means that if a patent disclosure includes many operable embodiments and only one inoperative embodiment, the claims may still be considered enabled if identifying the operable embodiments does not require undue experimentation.