OBJECTIVES: To compare total health care costs for a cohort of patients who received MTM (Medication therapy management) with controls among an eligible Medicaid managed care population. METHODS: A post-hoc analysis of a retrospective observational cohort study comparing MTM to usual care. The intervention population included patients aged 18-65 who opted-in to receive MTM services (n=1,007) compared with control patients who opted-out of MTM (n=13,614). All patients were followed for 12 months before the index/enrollment date and 12 months after the index date. Total, inpatient, outpatient, emergency, and pharmacy paid healthcare claims from Medicaid during the 12-month follow-up period was collected for all patients. T-tests and Chi-squared tests were used to compare patients’ differences in baseline characteristics. Stepwise regression was used to select baseline covariates to generate a propensity score based on receipt of MTM. An 8-digits to 1-digit Greedy matching algorithm was adapted for matching cases to controls. Unadjusted difference-in-differences (DID) was used to compare the means of log transformed healthcare costs between cases and controls. RESULTS: After matching, the differences of baseline covariates in cases and controls were reduced by mean absolute bias of -46.8%. The matched population used for analysis included 832 cases and 1664 controls. Mean total DID healthcare costs were significantly higher among the MTM intervention cases (Δ$3,614) compared with matched controls (Δ$-413; p<0.001). Pharmacy (drug) DID costs were significantly higher among the MTM intervention cases (Δ$3,284) compared to controls (Δ$-1,303; p<0.001). Inpatient, outpatient, and emergency department DID costs were not significantly different between cases and controls. CONCLUSIONS: The MTM intervention for this Medicaid population increased total healthcare costs. Increased pharmacy costs appear to drive the overall health care costs for MTM intervention.