What are the limitations of the safe harbor provision in 35 U.S.C. 121?

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 safe harbor provision in 35 U.S.C. 121 offers protection against certain double patenting rejections, but it has several important limitations. According to MPEP 804.01:

“The protection of 35 U.S.C. 121 is limited to divisional applications, and does not extend to continuation-in-part applications or continuation applications.”

Key limitations of the safe harbor provision include:

• It only applies to divisional applications, not continuation or continuation-in-part applications.
• The divisional application must be filed before the issuance of the patent on the other application.
• The claims in the divisional must maintain consonance with the original restriction requirement.
• It does not protect against all types of double patenting rejections, such as statutory double patenting.
• The protection can be lost if the restriction requirement is withdrawn, modified, or overruled.

Understanding these limitations is crucial for patent applicants to properly strategize their patent prosecution and avoid unexpected double patenting rejections.