Background: Evidence for community-based strategies to reduce inpatient detoxification readmission for opioid use disorder (OUD) is scant. A pilot program was designed to provide individualized structured treatment plans, including addressing prolonged withdrawal symptoms, family/systems assessment, and contingency management, to reduce readmission after the index inpatient detoxification., Methods: A non-randomized quasi-experimental design was used to compare the pilot facilities (treatment) and comparison facilities before and after the program started, i.e., a simple difference-in-differences (DID) strategy. Adults 18 years and older who met the Diagnostic and Statistical Manual of Mental Disorders version 5 criteria for OUD and had an inpatient detoxification admission at any OUD treatment facility in two study periods between 7/2016 and 3/2020 were included. Readmission for inpatient detoxification in 90-days after the index stay was the primary outcome, and partial hospitalization, intensive outpatient care, outpatient services, and medications for OUD were the secondary outcomes. Six statistical estimation methods were used to triangulate evidence and adjust for potential confounding factors between treatment and comparison groups., Results: A total of 2,320 unique patients in the pilot and comparison facilities with 2,443 index inpatient detoxification admissions in the pre- and post-periods were included. Compared with patients in comparison facilities, patients in the C.L.I.M.B. facilities had higher readmission in the pre-period (unadjusted readmission 17.0% vs. 10.6%), but similar rates in the post-period (12.3% vs. 10.6%) after the implementation of the pilot program. For 90-day readmission, all DID estimates were not statistically significant (adjusted estimates ranged from 6 to 9 percentage points difference favoring the C.L.I.M.B. program). There was no significant improvement in the secondary outcomes of utilizations in lower level of care and medications for OUD in C.L.I.M.B. facilities., Conclusions: We found a reduction in readmission in the pilot facilities between the two periods, but the results were not statistically significant compared with the comparison facilities and the utilization of lower level of care services remained low. Even though providers in the pilot OUD treatment facilities actively worked with health plans to standardize care for patients with OUD, more strategies are needed to improve treatment engagement and retention after an inpatient detoxification., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Luo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)