Calculating the Term of a Patent Can Be Challenging

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May 28, 2019

Questions concering the term or expiration date of a patent are common and can arise under a number of different circumstances. For instance, you may be wondering when your patent will expire, or in some cases, when someone else's patent will expire. Although these questions may be commonplace, they can also be complicated or challenging to answer.

As an example, the term of a patent is often not as easy as adding twenty years to the the filing date (in the case of a utility patent) or fifteen years to the issue date (in the case of a design patent). Rather, in additon to the type of the patent (i.e., utility patent, design patent or plant patent), there are a number of different factors that can impact the length of the patent or otherwise when the patent will expire, including, but not limited to, the filing date (e.g., whether the application that led to the patent was filed before, on or after June 8, 1995), whether the patent claims priority to a prior-filed U.S. or Patent Cooperation Treaty (PCT) patent application, whether there was a terminal disclaimer submitted with the patent application, whether the maintennce fees have been timely filed, or whether there are any applicable patent term adjustments as provided by 35 U.S.C. 154 or patent term extensions as provided by 35 U.S.C. 156.

Recognizing the difficultly involved in calculating the term of a patent, the U.S. Patent & Trademark Office now provides a Patent Term Calculator, which can be used as a starting point or estimator. However, if you have any questions regarding the expiraton of a patent, whether owned by you, your company or another, please contact us for assistance.