Part D Plans Generally Include Drugs Commonly Used by Dual-Eligible Enrollees: 2025

Why OIG Did This Review

• For dual-eligible enrollees—that is, people enrolled in both Medicare and Medicaid—access to prescription drugs is particularly important. Overall, they have very low incomes and—because they are more likely to be in poorer health than other people enrolled in Medicare—tend to use more Medicare services.
• Because Medicare prescription drug coverage is an important tool for ensuring access to prescription drugs, Congress mandated that OIG study whether Part D formularies cover prescription drugs commonly used by dual-eligibles enrollees.
• For this report, we determined whether the 378 unique formularies used by the 5,178 Part D plans operating in 2025 cover 194 of the 200 drugs most commonly used by dual-eligible enrollees. See the methodology for more information about how we determined the most commonly used drugs.

What OIG Found

• A majority of 2025 Part D plan formularies covered almost all commonly used drugs, and only a small number of commonly used drugs were not covered by most formularies. This is consistent with OIG’s annual findings since 2011.

What OIG Concludes

• Dual-eligible enrollees can expect to have access to most drugs in 2025, regardless of the Part D plan in which they are enrolled.