OBJECTIVES To evaluate the impact of a specialty care management program (PrecisionRx Pharmacy Management) on medication adherence, risk of hospitalization, and costs of care among MS patients. METHODS This study was a retrospective analysis of administrative claims from 13 geographically dispersed US commercial health plans. Patients aged 18-64 years with ≥2 claims of MS diagnosis and ≥1 MS medications (Interferon beta-1a, Interferon beta-1b, and Glatiramer acetate) from january 1, 2004 and April 30, 2008 were identified. For patients enrolled in PrecisionRx program (managed), index date was defined as the program participation date; for other patients (non-managed), index date was randomly assigned through Monte Carlo simulation with regard to the managed patients. At least 12 months of continuous eligibility pre- and post- index was required. Outcome metrics included medication adherence (measured by medication possession ratio (MPR)), risk of MS-related hospitalization, and MS-related costs. Multivariate analyses were performed to adjust for baseline demographics, baseline healthcare costs, and clinical characteristics. RESULTS Among 3862 patients identified, 79% were managed and 21% were non-managed patients. The multivariate analysis showed that compared with the non-managed group, the managed group had 0.21 higher MPR (95% CI: 0.19-0.23, p<0.001), were less likely to be hospitalized for MS (adjusted odds ratio: 0.53 (0.40-0.70), p<0.001), and had 25% higher MS-related costs (95% CI: 20%-31%, p<0.001), controlling for other covariates. The relatively larger increase in MS-related costs from pre-index to post-index among the managed group (median: $3791 vs. $2277) was primarily driven by larger increase in their pharmacy costs (median: $3968 vs. $1885). CONCLUSIONS Overall, this specialty care management program was associated with better medication adherence and lower risk of MS-related hospitalization. The associated higher MS-related costs among the managed group could be explained by their relatively larger increase in pharmacy costs, as expected due to better medication adherence and high costs of MS medication.