38 U.S.C. § 313: Availability of appropriations

(a) Funds appropriated to the Department may remain available until expended. (b) Funds appropriated to the Department may not be used for a settlement of more than $1,000,000 on a construction contract unless—(1) the settlement is audited by an entity outside the Department for reasonableness and appropriateness of expenditures; and (2) the settlement is provided for specifically in an appropriation law.