What are the most common grounds for rejection in patent applications?

The most frequent grounds for rejection in patent applications are based on prior art. As stated in the MPEP, By far the most frequent ground of rejection is on the ground of unpatentability in view of the prior art, that is, that the claimed subject matter is either not novel under 35 U.S.C. 102, or else it is obvious under 35 U.S.C. 103. This means that patent examiners most often reject claims because they find that the invention is either not new or is an obvious variation of existing technology.

To learn more:

• prior art
• novelty
• obviousness
• patent rejection