20 C.F.R. § 725.535
(d) Amounts paid or incurred or to be incurred by the individual for medical, legal, or related expenses in connection with this claim for State or Federal benefits (defined in paragraph (a) of this section) are excluded in computing the reduction under paragraph (b) of this section, to the extent that they are consistent with State or Federal Law. Such medical, legal, or related expenses may be evidenced by the State or Federal benefit awards, compromise agreement, or court order in the State or Federal benefit proceedings, or by such other evidence as the Office may require. Such other evidence may consist of: