29 CFR §4003.7

Except as provided in § 4003.22(b), a person aggrieved by an initial determination of PBGC covered by this part, other than an initial determination subject to reconsideration that is issued by a Department Director, has not exhausted his or her administrative remedies until he or she has filed a request for reconsideration under subpart C of this part or an appeal under subpart D of this part, whichever is applicable, and a decision granting or denying the relief requested has been issued.