1. Housing assistance fund (a) Definitions In this section: (1) Conforming loan limit The term conforming loan limit means the applicable limitation governing the maximum original principal obligation for a mortgage secured by a single-family residence, a mortgage secured by a 2-family residence, a mortgage secured by a 3-family residence, or a mortgage secured by a 4-family residence, as determined and adjusted annually under section 302(b)(2) of the Federal National Mortgage Association Charter Act ( 12 U.S.C. 1717(b)(2) ) and section 305(a)(2) of the Federal Home Loan Mortgage Corporation Act ( 12 U.S.C. 1454(a)(2) ). (2) Eligible household The term eligible household means a household whose income does not exceed 150 percent of the area median income for their household size, as determined by the Secretary of Housing and Urban Development. (3) Mortgage The term mortgage means a mortgage— (A) that is secured by the principal residence of a borrower