What is the difference between a 35 U.S.C. 111(a) and 111(b) application?

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 main difference between applications filed under 35 U.S.C. 111(a) and 111(b) lies in their purpose and requirements. According to MPEP 201.01:

• 35 U.S.C. 111(a) applications: These are for original (nonprovisional) patents. They require a specification, at least one claim, and drawings (when necessary).
• 35 U.S.C. 111(b) applications: These are for provisional patents. They do not require claims and are not examined on their merits.

The key differences are:

1. Examination: 111(a) applications undergo full examination, while 111(b) applications do not.
2. Duration: 111(a) applications can lead to granted patents, while 111(b) applications expire after 12 months.
3. Requirements: 111(a) applications have stricter formal requirements, including the need for claims.

Inventors often use 111(b) provisional applications to establish an early filing date before filing a more comprehensive 111(a) nonprovisional application.

For more information on 35 U.S.C. 111(a), visit: 35 U.S.C. 111(a).

For more information on nonprovisional application, visit: nonprovisional application.

For more information on patent application types, visit: patent application types.

For more information on provisional application, visit: provisional application.