Medicaid Enrollment And Prescription Use During Unwinding

Key Takeaways

• Continuous enrollment was associated with rising Medicaid enrollment and reimbursed prescriptions, followed by declines after unwinding began.
• Similar directional patterns were reported for chronic disease medications and pediatric-specific formulations, with the largest chronic-medication declines in states with the highest disenrollment.
• States with more protective unwinding policies had smaller enrollment declines and insignificant chronic-medication decreases, and the authors concluded that unwinding measurably affected prescription access.

Medicaid enrollment rose 2.42% per quarter during continuous enrollment, then fell 4.92% per quarter after unwinding began, reversing the earlier trend. In an interrupted time series analysis of Medicaid enrollment and reimbursed prescriptions, investigators examined quarterly state enrollment and estimated reimbursed prescriptions across the two policy periods. The cross-sectional study covered 2018 Q1 through 2024 Q1, with 2020 Q2 marking the start of continuous enrollment and 2023 Q2 marking the start of unwinding. Reimbursed prescription volume moved in the same direction as enrollment, although the change was smaller.

Investigators compared quarterly state Medicaid enrollment with estimated reimbursed prescriptions from 2018 Q1 through 2024 Q1 across both policy transitions. The analysis used interrupted time series methods, with log-transformed linear regression models listed in the abstract. In 2019 Q4, Medicaid enrollment stood at 71.4 million, alongside about 183.2 million reimbursed prescriptions. By 2023 Q2, enrollment peaked at 93.9 million and prescriptions reached 212.6 million. Prescription growth still did not match the full magnitude of enrollment growth.

During continuous enrollment, reimbursed prescriptions increased 1.85% per quarter, then declined 3.94% per quarter during unwinding. Similar directional patterns were reported for chronic disease medications and pediatric-specific formulations during those same periods. In the 2019 Q4 prescription mix, 59.1 million prescriptions treated chronic diseases, 30.3 million treated acute conditions, and 15.0 million covered other specified conditions. The study also included overall, state-stratified, and medication-subset analyses across the observation window. Medication use tracked enrollment changes, but the magnitude remained smaller.

State-level differences were most apparent during unwinding, when states with the highest disenrollment showed the largest decreases in chronic disease medication use. States with more protective policies had smaller enrollment declines and insignificant decreases in chronic medication use.

The authors linked unwinding to measurable changes in access to prescription medications and reported that protective policies mitigated those changes. The findings were framed around access-related prescription changes rather than patient-level clinical outcomes.