To evaluate changes in opioid prescribing and patient-reported outcomes after surgery following implementation of Michigan's prescription drug monitoring program (PDMP) use mandate in June 2018. Most states mandate clinicians to query prescription drug monitoring program (PDMP) databases before prescribing controlled substances. Whether these PDMP use mandates affect opioid prescribing and patient-reported outcomes after surgery is unclear, especially among patients with elevated "Narx" scores, a risk score for overdose death used in most PDMPs. We conducted an interrupted time series analysis of a statewide surgical registry linked to Michigan's PDMP database. Analyses included adults undergoing general surgical procedures during January 2017-October 2019. Outcomes included monthly mean days supplied in dispensed opioid prescriptions (those filled within 3 days of discharge) and monthly mean scores for 3 patient-reported outcomes (pain in the week after surgery, care satisfaction, regret undergoing surgery). Segmented regression models were used to assess for level and slope changes in outcomes in June 2018. Analyses were repeated among patients with Narx scores ≥200, a threshold that defines the top quartile. Analyses included 21,897 patients. The mandate was associated with a -0.5 (95% CI: -0.8, -0.2) level decrease in mean days supplied in dispensed opioid prescriptions, but not with worsened patient-reported outcomes. Findings were similar among patients with Narx scores ≥200. Following implementation of Michigan's PDMP use mandate, the duration of opioid prescriptions decreased, but patient-reported outcomes did not worsen. Findings suggest PDMP use mandates may not be associated with worsened experience among general surgical patients.