20 C.F.R. § 10.422
(a) In exercise of the discretion afforded under 5 U.S.C. 8135(a), OWCP has determined that lump-sum payments will not be made to persons entitled to wage-loss benefits (that is, those payable under 5 U.S.C. 8105 and 8106). Therefore, when OWCP receives requests for lump-sum payments for wage-loss benefits, OWCP will not exercise further discretion in the matter. This determination is based on several factors, including: