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Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2022


This data snapshot fulfills for 2022 the annual reporting mandate from the Patient Protection and Affordable Care Act (ACA). The ACA requires OIG to conduct a study of the extent to which formularies used by Medicare Part D plans include prescription drugs commonly used by dual eligible individuals (i.e., individuals who are covered by both Medicare and Medicaid). These individuals generally get drug coverage through Medicare Part D. Pursuant to the ACA, OIG must annually issue a study with recommendations as appropriate. This is the twelfth study that OIG has produced to meet this mandate.


For this data snapshot, we determined whether the 449 unique formularies used by the 5,288 Part D plans operating in 2022 cover the 200 prescription drugs most commonly used by dual eligibles. To create the list of the 200 drugs most commonly used by dual eligibles, we used the 2019 Medicare Current Beneficiary Survey-the most recent data available at the time of our study. Of the top 200 drugs, we analyzed 195 drugs. Three drugs are not eligible for Part D coverage, and we excluded two additional drugs from our analysis because we could not confidently project the use of these drugs to the entire dual-eligible population.


We found that dual eligibles have access to the majority of commonly used prescription drugs in 2022 via Part D plans, as we also found in previous years. A majority of the 449 Part D plan formularies covered almost all (at least 97 percent) of the drugs most commonly used by dual eligibles. Similarly, among Part D plans with premiums below the regional benchmark, a majority of formularies (95 of 132) covered at least 97 percent of the drugs commonly used by dual eligibles. This is important because when dual eligibles do not select their own Part D plans, CMS randomly assigns them to plans with premiums below the regional benchmark without considering their specific prescription drug needs. If dual eligibles' plans do not cover specific drugs, they have several options (switching plans, using an exceptions and appeals process, finding an alternative drug, or paying out of pocket), but these options require beneficiaries to take administrative actions and do not guarantee access to the drugs.


In general, dual eligibles have access to nearly all of the most commonly used prescription drugs via Part D plan formularies in 2022. A majority of these formularies covered almost all commonly used drugs, and only a small number of commonly used drugs were not covered by most formularies. These findings are largely unchanged from OIG's findings reported from 2011 through 2021. As mandated by the ACA, OIG will continue to monitor and produce annual reports on the extent to which Part D plan formularies cover drugs that dual eligibles commonly use. OIG has no recommendations at this time.