the Treasury not otherwise appropriated, for fiscal year 2019 and each fiscal year thereafter, $50,000,000, to remain available until expended, for incremental project-based voucher assistance or project-based rental assistance, to be allocated to States pursuant to the formula established under section 1338 of the Federal Housing Enterprises Financial Safety and Soundness Act of 1992 ( 12 U.S.C. 4568 ), to be used solely in conjunction with grant funds awarded under such section 1338. (3) Priority for housing the homeless (A) Priority During the first 5 fiscal years that amounts are made available under this subsection, the Secretary of Housing and Urban Development shall ensure that priority for occupancy in dwelling units described in subparagraph (B) that become available for occupancy shall be given to persons and households who are homeless (as such term is defined in section 103 of the McKinney-Vento Homeless Assistance Act ( 42 U.S.C. 11302 )). (B) Covered dwelling units A dwelling unit described in this subparagraph is any dwelling unit that— (i) is located in housing that was at any time provided assistance with any amounts from the Housing Trust Fund referred to paragraph (1) that were credited to such Trust Fund by such paragraph