What is the presumption of operability in patent law?

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 presumption of operability is a legal concept in patent law that assumes every patent is valid and operable. This is based on 35 U.S.C. 282, which states that patents are presumed valid. The MPEP section 716.07 elaborates on this, stating:

‘Since every patent is presumed valid (35 U.S.C. 282), and since that presumption includes the presumption of operability (Metropolitan Eng. Co. v. Coe, 78 F.2d 199, 25 USPQ 216 (D.C. Cir. 1935), examiners should not express any opinion on the operability of a patent.’

This means that patent examiners and others challenging a patent must assume that the patented invention works as described unless proven otherwise.