What is the primary focus of a patent examiner’s initial search?

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 primary focus of a patent examiner’s initial search is on the invention as described and claimed in the nonprovisional application. According to the MPEP, The first search should cover the invention as described and claimed, including the inventive concepts toward which the claims appear to be directed. It should not be extended merely to add immaterial variants. This means the examiner should thoroughly understand the invention and search for relevant prior art in patents and other published documents, including nonpatent literature (NPL).