BACKGROUND AND OBJECTIVES: Readmission to residential treatment increases healthcare costs, strains publicly funded systems, and may not adequately meet clients' needs. This study examined rates and predictors of readmission to residential treatment among clients transitioned from detoxification services.

METHOD: Data from 4915 clients admitted between April 2015 and March 2022, encompassing 10,463 treatment admissions, were analyzed. Logistic regression was used to compare readmitted with nonreadmitted clients, focusing on sociodemographic characteristics, primary substance of concern, and program-related variables.

RESULTS: Overall, 41.6% (n = 2046) of clients were readmitted, with a mean of 3.7 admissions, indicating that a small subgroup accounted for a disproportionate use of limited treatment capacity. Higher odds of treatment readmission were associated with opiate or alcohol use, unstable employment or marital status, detox noncompletion or repeated cycling between completion and noncompletion, transition delays exceeding 14 days, polysubstance use, urban-rural mobility, and use of multiple detox facilities. Lower odds of treatment readmission were observed in individuals using cocaine, those admitted to integrated facilities offering both detox and residential care, and clients with less frequent detox utilization.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE: Readmission to residential treatment is common and linked to both individual vulnerabilities and system-level factors. Strengthening protocols for alcohol and opioid use, enhancing coordination between detox and residential treatment, and targeting high-risk groups may reduce readmission. Interventions addressing non-completion of detox and delayed transitions could further reduce treatment readmission. This study uniquely examines readmission in relation to prior detoxification programs and clients' characteristics within a continuum-of-care framework.