What are intervening rights in patent reissue?

Intervening rights are defenses to patent infringement that arise from the reissue of an original patent. 35 U.S.C. 252 provides for two types of intervening rights:

1. Absolute intervening rights: These apply to parties who, prior to the reissue, made, purchased, offered to sell, used, or imported anything patented by the reissued patent.
2. Equitable intervening rights: These may be granted where substantial preparation was made before the reissue.

The MPEP cites: “Absolute” intervening rights are available for a party that “prior to the grant of a reissue, made, purchased, offered to sell, or used within the United States, or imported into the United States, anything patented by the reissued patent,” and “equitable” intervening rights may be provided where “substantial preparation was made before the grant of the reissue.”

These rights are designed to protect investments made before the reissue grant.

To learn more:

• intervening rights
• patent reissue
• absolute intervening rights
• equitable intervening rights