Can a patent with common inventors be used as prior art under pre-AIA 35 U.S.C. 102(e)?

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.

Yes, a patent with common inventors can be used as prior art under pre-AIA 35 U.S.C. 102(e) if the inventive entities are not identical. The MPEP clarifies this in MPEP 2136.04:

“The fact that the application and reference have one or more inventors in common is immaterial.”

This means that even if there are overlapping inventors, as long as the inventive entities are different (i.e., not all inventors are the same), the reference can be considered “by another” and used as prior art under pre-AIA 35 U.S.C. 102(e).