This bill amends Title XVIII of the Social Security Act to introduce a new phase-in for certain plasma-derived products under the Medicare Part D manufacturer discount program. This provision specifically targets biological products derived from human whole blood or plasma that were marketed as of August 16, 2022, modifying the calculation of their discounted price. Beginning in 2026, the legislation establishes a gradual reduction in the manufacturer discount percentage for these products over several years. For beneficiaries who have not yet met their annual out-of-pocket threshold, the discount percentage starts at 99% in 2026 and decreases to 90% by 2030. For beneficiaries who have exceeded their out-of-pocket threshold, the discount also begins at 99% in 2026 but further decreases to 80% by 2032. This phase-in does not apply to drugs dispensed to low-income subsidy beneficiaries or those from specified small manufacturers, maintaining existing exclusions.