From budget authority made available in appropriation Acts for fiscal year 1988, the Secretary shall enter into an annual contributions contract for a term of 180 months to obligate sufficient funds to provide assistance payments pursuant to section 8(b)(1) of the United States Housing Act of 1937 [
42 U.S.C.
1437f
(b)(1)] on behalf of 500 lower income families from budget authority made available for fiscal year 1988, so long as such families occupy properties in Jefferson County, Texas. If a lower income family receiving assistance payments pursuant to this subsection ceases to qualify for assistance payments pursuant to the provisions of section 8 of such Act [
42 U.S.C.
1437f] or of this subsection during the 180-month term of the annual contributions contract, assistance payments shall be made on behalf of another lower income family who occupies a unit identified in the previous sentence.