How does the USPTO handle indefiniteness rejections for computer-implemented functional claim limitations?

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 USPTO has specific guidance for handling indefiniteness rejections related to computer-implemented functional claim limitations. According to MPEP 2173.02:

“For a computer-implemented functional claim limitation, the specification must disclose an algorithm for performing the claimed specific computer function, or else the claim is indefinite under 35 U.S.C. 112(b).”

This means that when a claim includes a computer-implemented function, the specification must provide a clear algorithm or step-by-step process for performing that function. Without such disclosure, the claim may be rejected as indefinite.

The MPEP further clarifies:

• The algorithm can be expressed in various forms, such as a mathematical formula, prose, flow charts, or any other manner that provides sufficient structure.
• If the specification fails to disclose sufficient corresponding structure, material, or acts that perform the entire claimed function, then the claim is indefinite under 35 U.S.C. 112(b).
• The indefiniteness rejection should explain the specific reasons why the specification does not adequately describe the claimed function.

Examiners are instructed to consider the claim as a whole when evaluating indefiniteness, taking into account the knowledge of one skilled in the art and the disclosure in the specification.