ImportanceInsurers are increasingly limiting the duration of opioid prescriptions for acute pain. Among patients undergoing surgery, it is unclear whether implementation of these limits is associated with changes in opioid prescribing and patient-reported outcomes, such as pain.ObjectiveTo assess changes in surgical opioid prescribing and patient-reported outcomes after implementation of an opioid prescribing limit by a large commercial insurer in Michigan.Design, Setting, and ParticipantsThis was a cross-sectional study with an interrupted time series analysis. Data analyses were conducted from October 1, 2022, to February 28, 2023. The primary data source was the Michigan Surgical Quality Collaborative, a statewide registry containing data on opioid prescribing and patient-reported outcomes from adults undergoing common general surgical procedures. This registry is linked to Michigan’s prescription drug monitoring program database, allowing observation of opioid dispensing. The study included 6045 adults who were covered by the commercial insurer and underwent surgery from January 1, 2017, to October 31, 2019.ExposurePolicy limiting opioid prescriptions to a 5-day supply in February 2018.Main Outcomes and MeasuresAmong all patients, segmented regression models were used to assess for level or slope changes during February 2018 in 3 patient-reported outcomes: pain in the week after surgery (assessed on a scale of 1-4: 1 = none, 2 = minimal, 3 = moderate, and 4 = severe), satisfaction with surgical experience (scale of 0-10, with 10 being the highest satisfaction), and amount of regret regarding undergoing surgery (scale of 1-5, with 1 being the highest level of regret). Among patients with a discharge opioid prescription and a dispensed opioid prescription (prescription filled within 3 days of discharge), additional outcomes included total morphine milligram equivalents in these prescriptions, a standardized measure of opioid volume.ResultsAmong the 6045 patients included in the study, mean (SD) age was 48.7 (12.6) years and 3595 (59.5%) were female. Limit implementation was not associated with changes in patient-reported satisfaction or regret and was associated with only a slight level decrease in patient-reported pain score (−0.15 [95% CI, −0.26 to −0.03]). Among 4396 patients (72.7%) with a discharge and dispensed opioid prescription, limit implementation was associated with a −22.3 (95% CI, −32.8 to −11.9) and −26.1 (95% CI, −40.9 to −11.3) level decrease in monthly mean total morphine milligram equivalents of discharge and dispensed opioid prescriptions, respectively. These decreases corresponded approximately to 3 to 3.5 pills containing 5 mg of oxycodone.ConclusionsThis cross-sectional analysis of data from adults undergoing general surgical procedures found that implementation of an insurer’s limit was associated with modest reductions in opioid prescribing but not with worsened patient-reported outcomes. Whether these findings generalize to other procedures warrants further study.