OBJECTIVES: Buprenorphine-medication assisted treatment (B-MAT) is an effective treatment for opioid dependence (OD), but may be considered cost-prohibitive by patients and health plans who manage its use based on ingredient cost alone. This analysis was conducted to estimate economic costs and benefits of B-MAT for OD from the perspective of a health plan sponsor. METHODS: A longitudinal, multivariate analysis was conducted using service use claims data among a sample of Aetna members with full benefit coverage and one or more diagnoses of OD during the 48 month measurement period (Q1 2006 to Q4 2009).  OD members treated with B-MAT (n = 725) were compared to members not treated with B-MAT (n = 1410).  Two six-month measurement periods were constructed around the index date: a six month pre-period and a six month post-period. RESULTS: During the six-month post period, B-MAT members filled an average of 0.29 (P<0.001) more prescriptions and had an average of 0.21 more psychiatrist visits (P<0.001) than non B-MAT members, but utilized significantly fewer behavioral health inpatient hospital admissions (-0.82), behavioral health hospital days (-0.71), medical inpatient hospital days (-0.39), and emergency room visits (-0.31; P’s<0.001).  Concerning healthcare costs, B-MAT members spent $5305 less on inpatient hospital costs (P=0.002), $542 less on emergency room costs (P= 0.016), and $6,378 less on total health care costs per member compared to non B-MAT members (P =0.001). CONCLUSIONS: Though B-MAT patients incur higher pharmacy costs, they use fewer expensive health care services in other areas, resulting in an overall positive cost-benefit.  Assuming present results remain in direction and magnitude across other health plans, and from year to year, health plans can experience considerable savings using B-MAT as a first line of treatment for OD supported by outpatient services such as office based providers and counselors.