1. Short title This Act may be cited as the Ensuring Access to Lower-Cost Medicines for Seniors Act . 2. Requirements for PDP sponsors of prescription drug plans and Medicare advantage organizations offering MA–PD plans under part D of the Medicare program that use formularies (a) In general Section 1860D–4(b)(3) of the Social Security Act ( 42 U.S.C. 1395w–104(b)(3) ) is amended by adding at the end the following new subparagraphs: (J) Required inclusion of certain generic drugs and biosimilar biological products (i) In general Subject to the succeeding provisions of this subparagraph, with respect to a plan year beginning on or after January 1, 2025, the following rules shall apply: (I) If the formulary includes a part D reference drug, the formulary shall include each part D generic drug of such part D reference drug for which the wholesale acquisition cost is less than the wholesale acquisition cost of such part D reference drug. (II) If the formulary includes a part D reference biological product, the formulary shall include at least one part D biosimilar biological of such part D reference biological product for which the wholesale acquisition cost is less than the wholesale acquisition cost of such part D reference biological product (if one or more such part D biosimilar biologicals is available). (ii) Determinations and implementation Determinations of part D generic drugs and part D biosimilar biological products described in subclauses (I) and (II) of clause (i) and implementation of formulary requirements under clause (i) shall be made by PDP sponsors offering prescription drug plans in accordance with uniform requirements established by the Secretary (by program instruction or otherwise), which shall provide for such determinations to be made as of specified dates (in the case of determinations during a plan year, on a quarterly basis), and for any associated formulary changes to be implemented promptly thereafter (in accordance with timeframes specified by the Secretary). Such uniform requirements