This bill proposes to amend the Internal Revenue Code of 1986 by introducing regional cost-of-living adjustments to individual income tax rates, effective for taxable years beginning after December 31, 2026. Its core purpose is to adjust the minimum and maximum dollar amounts for each income tax rate bracket based on the cost of living in an individual's primary residence, rather than changing the tax rates themselves. An applicable multiplier , prescribed annually by the Secretary of the Treasury for each statistical area, will be used for these adjustments. This multiplier is determined by comparing an area's cost-of-living differential to the national average. For example, areas with a differential exceeding 125% will use a multiplier of 90% of that differential, while those between 97% and 125% will use 1.05, and areas at or below 97% will use 1. The Secretary of Commerce is mandated to determine and publish a cost-of-living index for each statistical area annually, using a methodology similar to Regional Price Parities indexes. These statistical areas encompass metropolitan statistical areas and the non-metropolitan portions of each state, aiming to provide targeted tax relief by effectively widening tax brackets in regions with higher living expenses.