The cost of providing and receiving treatment for opioid dependence can determine its adoption. To compare the cost of clinic-based methadone (MC, n=23), office-based methadone (MO, n=21), and office-based buprenorphine (BO, n=34) we performed an analysis of treatment and patient costs over 6 months of maintenance in patients who had previously been stabilized for at least 1 year. We performed statistical comparisons using ANOVA and chi-square tests and performed a sensitivity analysis varying cost estimates and intensity of clinical contact. The cost of providing 1 month of treatment per patient was $147 (MC), $220 (MO) and $336 (BO) (p<0.001). Mean monthly medication cost was $93 (MC), $86 (MO) and $257 (BO) (p<0.001). The cost to patients was $92 (MC), $63 (MO) and $38 (BO) (p=0.102). Sensitivity analyses, varying cost estimates and clinical contact, result in total monthly costs of $117 to $183 (MC), $149 to $279 (MO), $292 to $499 (BO). Monthly patient costs were $84 to $133 (MC), $55 to $105 (MO) and $34 to $65 (BO). We conclude that providing clinic-based methadone is least expensive. The price of buprenorphine accounts for a major portion of the difference in costs. For patients, office-based treatment may be less expensive.