Section 154(b) of the Patent Act includes an odd provision indicating that a "third party" may not appeal or challenge the USPTO's patent term adjustment determination prior to the patent issues:
35 U.S.C. 154(b)(4)(B): The determination of a patent term adjustment [PTA] under this subsection shall not be subject to appeal or challenge by a third party prior to the grant of the patent.
Although not a necessary conclusion, this provision prompts a negative implication that a the PTA may be subject to challenge by a third party after the grant of patent. Of course, the statute does not explicitly create that right.
As it stands, third party challenges to patent rights come in three forms: (1) interference proceedings; (2) inter partes and ex parte reexaminations; and (3) patent infringement litigation (including declaratory judgment actions). However, allegations of an improper PTA calculation do not create grounds for starting either an interference or reexamination. As discussed, improper PTA calculation could be the proper subject of a declaratory judgment challenge. However, by statute, it appears that that challenge is limited to instances when potentially infringing actions are occurring during the extension portion of the term.
All this leaves me confused as to why the provision is law.