Patent Term Extension List

By Shelly Morgan

The term of a patent is 20 years. During this time, the patent owner can exclude others from making and using the invention. This 20-year-period can be extended, under certain circumstances. The patent extension list, published by the U.S. Patent and Trademark Office, includes all patents whose terms have been extended under 35 USC 156. The list informs the public of how long the patent term was extended.


Bringing a drug or medical device to market involves navigating a complex mix of regulatory laws, some of which seem to work against each other. For example, a drug company might spend years shepherding the patent application for a drug through the U.S. Patent and Trademark Office. Even if the patent issues, the company might still be unable to bring the drug to market because the FDA has not yet approved the drug. This has the practical effect of shortening the patent term.

Getting Listed

The owner of a patent can apply to have a patent put on the patent term extension list by submitting an application for extension of patent term, under 35 USC 156 within 60 days of receiving permission to market the drugs. The USPTO reviews the application and determines how much additional time should be tacked on to the 20- year-patent term. Regardless of the duration of regulatory delay, a patent term cannot be extended more than five years.

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List Information

The patent term extension list is organized according to patent number, with the oldest patent numbers appearing first. Other information included on this list is the trade name of the product, the original expiration date, the number of years the patent term was extended, the date the application for extension was approved and the extended expiration date.

Important Distinctions

Patent term extension is not the same as patent term adjustment. While both extension and adjustment affect the term of a patent, patent term adjustment extends patent term to compensate for delays that the USPTO has caused, and patent term extension extends term to compensate for delays that the regulatory process has caused. Patents that have been granted extra time under patent term adjustment do not appear on the patent term extension list.

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