A cross-sectional study evaluated the impact of a state-specific prescription duration limit policy on opioid prescribing patterns among Medicaid enrollees in West Virginia. The policy, implemented in June 2018, set different limits based on clinical settings: 7 days for adults in outpatient settings, 4 days for adults in emergency departments, and 3 days for pediatric patients. The study analyzed data from 2017 to 2019, focusing on opioid-naive patients aged 12 to 64 years, excluding those with cancer or Medicare coverage. The results showed that the policy significantly reduced the proportion of opioid prescriptions exceeding the set limits. For adults in outpatient settings, the proportion of prescriptions exceeding the 7-day limit decreased by 56.8%, while for adults in emergency departments, it decreased by 37.5%. For pediatric patients, the proportion of prescriptions exceeding the 3-day limit decreased by 26.5%. Additionally, prescription lengths for adults in outpatient settings decreased by 15.26%, and for pediatric patients, by 10.17%. The study also examined whether prescribers compensated for shorter prescriptions by writing stronger or more frequent prescriptions. However, no significant increase in prescription strength was observed for pediatric patients, and there was a decrease in high-dose prescriptions for adults. The findings suggest that the policy effectively reduced prescription lengths without leading to compensatory prescribing. The study highlights the importance of tailoring opioid prescription limits to specific clinical settings. While the policy reduced prescription lengths, the long-term clinical outcomes, such as opioid use disorder incidence or unintended consequences like shifts to illicit opioids, remain unclear. The study underscores the need for further research to evaluate the broader implications of such policies. The results indicate that state-specific policies may be more effective in curbing prescription duration, but their impact on patient outcomes requires further investigation.A cross-sectional study evaluated the impact of a state-specific prescription duration limit policy on opioid prescribing patterns among Medicaid enrollees in West Virginia. The policy, implemented in June 2018, set different limits based on clinical settings: 7 days for adults in outpatient settings, 4 days for adults in emergency departments, and 3 days for pediatric patients. The study analyzed data from 2017 to 2019, focusing on opioid-naive patients aged 12 to 64 years, excluding those with cancer or Medicare coverage. The results showed that the policy significantly reduced the proportion of opioid prescriptions exceeding the set limits. For adults in outpatient settings, the proportion of prescriptions exceeding the 7-day limit decreased by 56.8%, while for adults in emergency departments, it decreased by 37.5%. For pediatric patients, the proportion of prescriptions exceeding the 3-day limit decreased by 26.5%. Additionally, prescription lengths for adults in outpatient settings decreased by 15.26%, and for pediatric patients, by 10.17%. The study also examined whether prescribers compensated for shorter prescriptions by writing stronger or more frequent prescriptions. However, no significant increase in prescription strength was observed for pediatric patients, and there was a decrease in high-dose prescriptions for adults. The findings suggest that the policy effectively reduced prescription lengths without leading to compensatory prescribing. The study highlights the importance of tailoring opioid prescription limits to specific clinical settings. While the policy reduced prescription lengths, the long-term clinical outcomes, such as opioid use disorder incidence or unintended consequences like shifts to illicit opioids, remain unclear. The study underscores the need for further research to evaluate the broader implications of such policies. The results indicate that state-specific policies may be more effective in curbing prescription duration, but their impact on patient outcomes requires further investigation.