1. Short title This Act may be cited as the Affordability and Fairness for Mountain Communities Act of 2023 . 2. Waiver program for ZIP Code localization of area median income calculations (a) In general Not later than 90 days after the date of enactment of this Act, the Secretary of Housing and Urban Development shall establish a waiver program to be known as the Area Median Income Localization Waiver (in this Act referred to as the waiver program ). (b) The Waiver Program The waiver program established by the Secretary pursuant to subsection (a) shall allow a county government, or corresponding functional unit of government, to calculate area median income for covered programs using— (1) a ZIP Code as the area for calculation; and (2) a group of counties that each share a border with such county as the area for calculation. (c) Application A county government, or a corresponding functional unit of government, may apply to participate in the waiver program by submitting an application to the Secretary at such time and in such manner as the Secretary may reasonably require. (d) Selection The Secretary shall grant a waiver to each county government, or corresponding functional unit of government, that submits an application pursuant to subsection (c). (e) Use of Waiver A county government, or corresponding functional unit of government, that receives a waiver under subsection (d) may, with respect to a covered program, calculate area median income using— (1) a ZIP Code as the area for calculation; (2) a group of counties that each share a border with such county as the area for calculation