What is double patenting?

Double patenting is a judicial doctrine that prevents the unjustified extension of patent exclusivity beyond the term of a patent. There are two types of double patenting rejections:

• Statutory double patenting under 35 U.S.C. 101, which prohibits claiming the same invention twice
• Nonstatutory double patenting, which is based on a judicially created doctrine to prevent unjustified timewise extension of patent rights

As stated in MPEP 804: “The doctrine of double patenting seeks to prevent the unjustified extension of patent exclusivity beyond the term of a patent.”

To learn more:

• double patenting
• patent term
• patent exclusivity
• statutory double patenting
• nonstatutory double patenting