How are pending U.S. patent applications treated in terms of confidentiality and 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.

Pending U.S. patent applications are generally kept confidential, but there are important exceptions and considerations:

• Most pending applications are preserved in confidence as per 37 CFR 1.14(a).
• Exceptions include published applications, reissue applications, and applications where public inspection has been granted.
• Applications with common assignees or inventors may be used for certain rejections, even if not published.

The MPEP provides specific guidance:

“If the copending applications differ by at least one inventor and at least one of the applications would have been obvious in view of the other, a provisional rejection over 35 U.S.C. 102(a)(2) or pre-AIA 35 U.S.C. 102(e) or 35 U.S.C. 103 is made when appropriate.”

For more information on rejections involving pending applications, refer to:

• MPEP § 804 for double patenting rejections
• MPEP §§ 2136.01, 2146.03(a) and 2154.01(d) for provisional rejections