This bill modifies the low-income housing tax credit program to encourage the construction and renovation of affordable housing near public transportation. Under the legislation, developers who build new affordable housing or rehabilitate existing affordable housing within half a mile of rail, bus, harbor, or waterway stations in designated high-density areas would receive a 150 percent increase in their tax credit eligibility, meaning they can claim significantly larger tax credits. Hawaii, Alaska, and U.S. territories receive an even larger boost of 155 percent to account for higher development costs in those areas. The bill limits these designations so that no more than 20 percent of any metropolitan area's population can live in these transit-oriented zones, preventing overconcentration in single regions. Additionally, the bill requires the Department of Housing and Urban Development to study regional cost-of-living differences related to transit access and submit recommendations within one year on how to adjust tax credit allocations by state to better reflect these variations.