This study examines the generalizability of a successful care management bridging strategy implemented by a behavioral health managed care organization to reduce readmission in psychiatric and substance use disorder (SUD) populations. The sample included 1724 individuals with a psychiatric or SUD hospitalization or detoxification service within 30-days of a prior SUD or inpatient event; 1243 Medicaid-enrolled adults received the intervention plus usual care, and 481 individuals received only usual care. Results included lower readmission to SUD facilities (p = .0012) and reduced odds of readmission among individuals with a SUD event (OR = 0.49, p = .0006) for the intervention versus the comparison group. Likelihood of readmission was higher for those with dual diagnoses (OR = 1.72, p = .0002) or in urban settings (OR = 1.47, p = .0010), with some evidence of the intervention's success in these populations. Care management bridging strategies may be more effective for individuals who utilize SUD services and others who need help navigating complex systems of care.