What is the significance of the publication date for a U.S. patent document in prior art rejections?

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 publication date of a U.S. patent document is crucial for determining its eligibility as prior art in patent rejections. According to MPEP 2126:

“The date that the patent is made available to the public is the date it is available as a 35 U.S.C. 102(a) or pre-AIA 35 U.S.C. 102(a) and (b) reference.”

This means that the publication date, rather than the filing date or issue date, determines when a patent document becomes available as prior art. For rejections under 35 U.S.C. 102(a) or pre-AIA 35 U.S.C. 102(a) and (b), the critical date is when the document becomes publicly accessible.