Impacts of Medicaid prescription cap policies on health outcomes are understudied.

Prescription cap policies were associated with increased hospitalization risk.

Cap policies were not associated with emergency department use or mortality.

Strict drug limits (3–4 monthly) were associated with higher hospitalization risk.

Cap exemptions for opioid use disorder medications may reduce unintended outcomes.

Twelve state Medicaid programs limit the monthly number of covered prescriptions. Such cap policies may force enrollees to forego essential medications with important health consequences. We aimed to determine the impact of cap policies on acute care use and all-cause mortality among enrollees with opioid use disorder (OUD).

Using 2016–2019 T-MSIS Analytical Files, we propensity-score matched enrollees with OUD in 12 states with cap policies and 26 states without cap policies. Outcomes measured over 12 months included emergency department (ED) visits, hospitalization, and all-cause mortality and were analyzed via generalized linear regression models. We conducted subgroup analyses by use of medications for OUD (MOUD) and comorbidity level and sensitivity analyses to examine the role of cap policy characteristics.

Unadjusted risks were 64.0 % vs. 62.5 % for ED visits, 27.6 % vs. 27.5 % for hospitalizations, and 3.2 % vs. 2.7 % for mortality in cap states and non-cap states, respectively. After adjustment, hospitalization risk was higher (RR=1.89, 99.5 %CI:1.13,3.16) in cap states than non-cap states whereas ED visits and mortality did not differ. There were largely no outcome differences by cap status in subgroups. Strict prescription limits allowing 3–4 prescriptions monthly (RR=1.90, 95 %CI:1.09,3.30) and lack of MOUD exemptions (RR=2.23, 95 %CI:1.32,3.78) were associated with increased hospitalization risk relative to non-cap states.

Medicaid prescription cap policies were associated with increased hospitalization risk, but there were no differences in ED use or all-cause mortality. Cap policies may undermine the health of individuals with OUD and could be counterproductive to state efforts to curb Medicaid spending.

Opioid use disorder

Medicaid

Prescription limit policies

Health outcomes

© 2025 The Authors. Published by Elsevier B.V.