US SB2638

Amends the Low-Income Housing Tax Credit (Section 42 of the Internal Revenue Code) to allow 130% of rehabilitation expenditures to be counted for existing buildings that achieve enhanced energy performance standards

Buildings qualify for the bonus by either meeting advanced building construction standards set by the Secretary of Energy within 180 days, or implementing a qualified retrofit plan that reduces site energy usage intensity by at least 50%

Provides an additional bonus of 160% of rehabilitation expenditures for buildings in high-cost areas that also achieve enhanced energy performance

Requires qualified retrofit plans to be prepared and certified by a licensed architect, licensed engineer, or other qualified professional as designated by the Secretary of Energy

Applies to buildings receiving housing credit allocations or bond financing issued after December 31, 2025