Project Summary The U.S. is facing an opioid-related public health crisis, and states have responded with a range of policies and initiatives, many of which are intended to decrease the widespread availability of opioid analgesics. Our understanding of the impact of these policies is still evolving, results of studies have been mixed, and no studies have examined to what extent policies have decreased potentially inappropriate prescribing while leaving likely appropriate prescribing untouched. To assess the impact of state policies and initiatives on overall opioid prescribing rates, likely appropriate prescribing, and potentially inappropriate prescribing, this project will produce empirical findings addressing these gaps using Medicare claims data for disabled beneficiaries, as well as IQVIA data which covers an estimated 88% of prescriptions filled at U.S. pharmacies. It will also examine how policies affect opioid prescription fills for historically underserved and high-risk populations. The results will inform state policymaking efforts related to the opioid crisis.