OBJECTIVES:  To evaluate the clinical and budgetary impact of continuous use of a 24-hour wearable basal-bolus insulin delivery device (IDD) in patients with suboptimally controlled diabetes previously administering multiple daily injections (MDI) of insulin. METHODS:  An electronic medical records database was queried to identify patients exceeding glycemic targets (A1C >7.0%) switched to V-Go IDD from MDI. Evaluated variables were extracted at baseline and up to 3 follow-up visits, post IDD initiation. Clinical and pharmacy budget comparisons to baseline were evaluated in patients with ≥ 5 months of continuous IDD use during the observation period. Impact to pharmacy budget per patient was derived by applying average unit pricing from market leaders for both basal and prandial insulins as well as pricing for insulin delivery via pen needles/syringes and V-Go IDD for prescribed insulin therapy. All costs were based on a normalized 30-day supply and published wholesale acquisition costs (WAC) in 2016 U.S. dollars as of December 31, 2016. RESULTS:  Evaluated patients (N=86) had a mean baseline A1C of 9.2 ± 1.4%, duration of diabetes 15 ± 9 years, weight 98 ± 19 kg, and insulin total daily dose (TDD) 108 ± 48 units/day with an associated insulin therapy direct pharmacy cost of $924.80 ± $392.90 per patient/month. After a mean duration of 29 ± 5 weeks of administering insulin with an IDD, A1C was reduced by 1.2 ± 1.4%, p<0.0001, TDD decreased by 44% to 61 ± 19 units/day, p<0.0001 and direct insulin therapy costs were reduced to $778.80 ± $154.20, p=0.001 for a savings of $146.00 ± $378.60 per patient/month. Weight and patient reported hypoglycemia remained similar to baseline. CONCLUSIONS:  Switching from MDI to basal-bolus therapy delivered with V-Go IDD was associated with significant reductions in A1C and insulin requirements and resulted in significant savings to the pharmacy budget.