the Secretary of Housing and Urban Development (in this section referred to as the Secretary ), $1,000,000,000 for fiscal year 2020, to remain available until expended, for incremental emergency vouchers under subsection (b). (b) Emergency vouchers (1) In general The Secretary shall provide emergency rental assistance vouchers under this subsection, which shall be tenant-based rental assistance under section 8(o) the United States Housing Act of 1937 ( 42 U.S.C. 1437f(o) ). (2) Selection of families (A) Mandatory preferences Each public housing agency administering assistance under this section shall provide preference for such assistance to eligible families that are— (i) homeless (as such term is defined in section 103(a) of the McKinney-Vento Homeless Assistance Act ( 42 U.S.C. 11302(a) )