What is the critical reference date for pre-AIA 35 U.S.C. 102(e) prior art?

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 critical reference date for pre-AIA 35 U.S.C. 102(e) prior art is an important concept in determining whether a reference qualifies as prior art under this section. While the MPEP excerpt provided doesn’t give a specific definition, it refers to MPEP § 2136.03 for more information:

“see MPEP § 2136.03 regarding critical reference date of pre‑AIA 35 U.S.C. 102(e) prior art”

Generally, the critical reference date for a U.S. patent or U.S. patent application publication under pre-AIA 35 U.S.C. 102(e) is the earliest effective U.S. filing date. This could be:

• The actual filing date of the U.S. application
• The filing date of a prior application if the reference is entitled to claim the benefit of an earlier filing date under 35 U.S.C. 120, 121, or 365(c)

For a more detailed explanation, please refer to MPEP § 2136.03.