What are the key requirements under 35 U.S.C. 112 in patent examination?

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.

35 U.S.C. 112 sets forth several important requirements for patent applications. According to MPEP 2103, the key requirements under 35 U.S.C. 112 are:

35 U.S.C. 112(b) Requirements:

1. The claims must set forth the subject matter the inventor regards as the invention
2. The claims must particularly point out and distinctly claim the invention
   • Claims must define the invention with reasonable precision and particularity
   • The scope of means-plus-function limitations is defined by the corresponding structure, material, or acts described in the specification and their equivalents

35 U.S.C. 112(a) Requirements:

1. Adequate Written Description
   • The specification must reasonably convey to those skilled in the art that the inventor was in possession of the claimed invention as of the date of invention
2. Enablement
   • The specification must enable a person skilled in the art to make and use the claimed invention without undue experimentation
3. Best Mode
   • The specification must disclose the best mode contemplated by the inventor for carrying out the invention

The MPEP notes, An application will be deficient under the first requirement of 35 U.S.C. 112(b) when evidence outside the application as filed shows that the inventor regards the invention to be different from what is claimed.

Examiners are expected to evaluate applications for compliance with all these requirements during the examination process.