38 USC 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.