What circumstances can lead to the rejection of a previously allowed patent claim?

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 rejection of a previously allowed patent claim is an unusual occurrence that typically happens under specific circumstances. According to MPEP 706.04, the main reason for such a rejection is the discovery of new prior art. This is evident from the language used in Form Paragraph 7.50:

“The indicated allowability of claim [1] is withdrawn in view of the newly discovered reference(s) to [2].”

Circumstances that may lead to the rejection of a previously allowed claim include:

• Discovery of new prior art that wasn’t considered in the initial examination
• Identification of a clear error in the previous action
• New interpretation of the claim language in light of newly discovered information

It’s important to note that such rejections are not made lightly and require careful consideration by a primary examiner. The USPTO emphasizes that “great care should be exercised in making such a rejection.”