Some state Medicaid programs place a cap on the monthly number of covered prescription fills, including medications for opioid use disorder (MOUD)–the most effective OUD treatments. Methods Between 2023 and 2024, we employed a quasi-systematic 3-step process (online search, survey of Medicaid experts, request-for-information) to identify contemporary Medicaid cap policy information and conducted a content analysis of cap policies. Results Of the 12 states with contemporary prescription cap policies, 9 operated general caps and 3 operated caps for controlled substances. Across states, caps ranged from 3-6 monthly prescriptions. All states had exemptions based on beneficiary characteristics (eg, age, health conditions) or medication type (eg, contraceptives, antipsychotics), 6 of which had cap override policies, and 5 had MOUD-specific exemptions. Conclusion Our search identified a dearth of publicly accessible, contemporary information on Medicaid cap policies, indicating a potential barrier to beneficiaries' understanding their prescription drug benefits. Further, although all states provided some type of policy carveout, half of the Medicaid programs operating caps did not exempt MOUD, which may negatively impact access to medically necessary medications for Medicaid beneficiaries with OUD.