Post Grant Procedures at the USPTO

Once a patent is issued by the USPTO, the interactions between the patentees and the USPTO with respect to that patent will greatly diminish but will not cease. At a minimum, the patent assignees will need to keep current with the patent maintenance fees if they wish the patent to remain enforceable over its entire lifetime (discussed in section 2.2.a). 

In addition to the mandatory maintenance fees, there are certain postgrant procedures that can take place under special circumstances. For example, patent interferences occur where a contest is waged in the USPTO to determine the first inventor of contested subject matter. These contests may occur between two or more applicants 

---