How Terminal Disclaimer Effects Life of a U.S. Patent?

A terminal disclaimer is a statement by which an applicant disclaims or dedicates to the public some part of term of the patent or complete term of a patent which is under examination at USPTO. Thus, an application for the patent, when filed in USPTO, faces rejections such as double patenting (discussed below in detail), then a terminal disclaimer is filed. 

This is done in order to overcome double patenting rejection by patent examiner in USPTO. If the United States Patent and Trademark Office (USPTO) gives a second patent to the inventor, similar to one already owned by the inventor, the applicant will have to file a terminal disclaimer for the second patent in order to overcome double patenting rejection.  

Thus, one should note that by filing a terminal disclaimer, the applicant/inventor are disowning or disclaiming some term of their patent to be granted, thus the life of the patent will not extend rather it will decrease or be cut to be not more than life of the parent application. Therefore, we can say that the disclaimed patent (patent under examination, yet to be granted) cannot extend beyond the life or term of the parent patent or prior patent, on the basis of which, double patenting rejection was asserted. Terminal disclaimers can nullify or disclaim potential patent term adjustment for the disclaimed patent in such a way that its life or term will not exceed the life of other patent. 

When an applicant files an application by making very small changes to already existing patent owned by the same applicant, the newly filed application may be granted to the applicant but under certain conditions.  

In other words, a patent can’t be filed twice by just introducing small changes. The USPTO applies double patenting rejection. In order to overcome this, one must file a terminal disclaimer. 

Filing a terminal disclaimer will help you have a patent with small changes to the already existing patent just by reducing or disclaiming or disowning the term of the newly filed application to be not more than that of the original patent. Hence, the second patent (on which terminal disclaimer is filed) will also expire when the first one also expires. Also, the terminal disclaimer is filed on the second patent only when the inventor/applicant owns all rights to both the patents. If under any circumstances, the first patent expires, or is sold, the inventor or applicant would not be able to enforce the second patent.  

Further, if multiple patents or applications are mentioned or disclosed in the terminal disclaimer, the earliest filing date of a patent/application mentioned is considered for disclaiming the term of the patent. 

The only exception is when the first patent is abandoned such as due to non-payment of fees, the second patent (with terminal disclaimer) will complete its term, but not beyond the true life of the first patent had it not been abandoned. 

Additionally, terminal disclaimer should be used following any alterations to the patent term, which will be covered in more depth below. Furthermore, a terminal disclaimer may be revoked prior to the grant of the patent by submitting a petition under 37 C.F.R. 1.182 asking for the revocation of the recorded terminal disclaimer. A terminal disclaimer, however, once a patent has been granted, it cannot be cancelled.