This legislation, known as the "John W. Walsh Alpha-1 Home Infusion Act of 2025," aims to expand Medicare coverage for individuals suffering from Alpha-1 Antitrypsin Deficiency Disorder (AATD). It specifically amends Title XVIII of the Social Security Act to include AATD treatment as a covered medical service under Medicare Part B , ensuring eligible beneficiaries can receive necessary care for this condition. The bill defines AATD treatment as augmentation therapy , involving Alpha-1 Proteinase Inhibitor, furnished in an individual's home by qualified home infusion therapy suppliers. To be eligible for this coverage, beneficiaries must be under the care of an applicable provider, enrolled in both Medicare Parts A and B, and not currently enrolled in a Medicare Advantage plan. Furthermore, the bill mandates the establishment of a new Medicare payment system to reimburse qualified home infusion therapy suppliers for intravenous administration kits and up to two hours of nursing services provided in coordination with the augmentation therapy. These significant changes are slated to take effect for items and services furnished on or after January 1, 2027, enhancing access to critical home-based care.