Cover: Evaluation of the Part D Senior Savings Model

Evaluation of the Part D Senior Savings Model

First Year of the Model Test (2021)

Published in: Centers for Medicare & Medicaid Services website (2023)

Posted on rand.org Jan 11, 2024

by Erin Audrey Taylor, Dmitry Khodyakov, Michael Dworsky, Christine Buttorff, Zachary Predmore, Lane F. Burgette, Stacie B. Dusetzina, Preethi Rao, Asa Wilks, Shiyuan Zhang, et al.

In 2021, the Center for Medicare & Medicaid Innovation began testing the effects of lower, predictable cost sharing for insulin as part of the Part D Senior Savings (PDSS) Model. RAND researchers conducted a mixed-methods evaluation of the impact this Model test had on participating Part D plans -- Medicare Advantage Prescription Drug plans (MA-PDs) and stand-alone Prescription Drug Plans (PDPs) -- as well as beneficiaries, insulin manufacturers, and the Centers for Medicare & Medicaid Services (CMS) on various outcomes in the first year after the start of the Model test. Early evaluation results show strong evidence of positive impacts on insulin users in the form of increased utilization of insulins and decreased out-of-pocket (OOP) costs. However, total Part D costs increased for non insulin users enrolled in participating PDPs. Although our analyses indicate that plans and CMS did not experience meaningful changes to their costs, manufacturers may have increased their total rebate payments to plans and increased their coverage gap discount payments as a result of the Model test. Together these findings suggest that, in its first year, the PDSS Model successfully reduced OOP costs for insulin users without shifting costs to plans or CMS.

A separate Model overview summarizes the 2021 outcomes of an evaluation of the Model test.

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