OBJECTIVES: In September 2023, CMS announced the top 10 drugs subjected to price negotiations under the IRA. These drugs accounted for over $50 billion in gross drug costs covered by Part D from June 2022 to May 2023. This study examines the beneficiaries that would be impacted by the price negotiations. We focused on patient demographics, hierarchical condition category (HCC), patient liability (patient out-of-pocket [OOP], low-income subsidy [LIS] payments, and other payers), and the month in which beneficiaries surpass the $2,000 OOP threshold.

METHODS: This study analyzed the 100% Medicare Part D Event claims data (PDE) files in 2022. Beneficiaries were selected if they had at least one prescription of the top 10 drugs. Demographic information was obtained from the Master Beneficiary Summary File (MBSF).

RESULTS: In 2022, 7,790,044 patients (Male=49%, White=77%, non-LIS=65%) used one or more of the 10 drugs (15% of Part D enrollees). A higher proportion of LIS beneficiaries were on insulin aspart (62%), etanercept (56%), sitagliptin (53%), and ustekinumab (53%) compared to non-LIS beneficiaries. Hispanic beneficiaries averaged the highest amount of liability for 8 out of the 10 drugs (highest: ustekinumab - $2,166) followed by Asian beneficiaries (highest: rivaroxaban $340). Over 50% of LIS beneficiaries exceed the $2,000 OOP threshold in June whereas 50% of non-LIS beneficiaries exceed the threshold in September. Black beneficiaries had the highest average HCC count of 4.6 whereas Asian beneficiaries had the lowest with 3.7.

CONCLUSIONS: Nearly 8 million Part D beneficiaries spent over $3.4 billion in OOP costs on the 10 drugs. Lower negotiated prices would lower beneficiaries' drug costs and potentially increase access to the selected drug. Black, Hispanic, and Asian LIS beneficiaries will be disproportionately impacted by the price negotiations. Further research is warranted to assess the medication usage of these initial drugs and other drugs that become subject to price negotiations.