OBJECTIVES:  1) To estimate the time and cost of discharge for patients receiving the current antithrombotic standard of care, warfarin +/- a heparin product at a large US academic medical center, and 2) to estimate the system-level impact of a hypothetical new oral antithrombotic in terms of improved discharge efficiency. METHODS:  Data were obtained from 2010 institutional metrics: patient volume, major diagnoses (e.g., orthopedic surgery, atrial fibrillation), and resource requirements (time and cost of personnel providing antithrombotic discharge counseling; time and cost of INR-related discharge delays). Metrics were coded as inputs in a MS Excel model to estimate the potential time and cost impact of changes in patient volume, personnel providing counseling, or addition of novel oral agents to the formulary. It was assumed that 80% of warfarin patients would receive the novel antithrombotic, that these drugs would reduce discharge counseling time by 70%, and would not require INR testing. The cost per day of the new agent was assumed to be $7 versus $0.82 for warfarin, and the bed of discharged patients was assumed to be refilled with a new patient 100% of the time at a reimbursement rate of $1500/day. RESULTS:  Based on 1000 patients with a LOS of 4 days, efficiency impacts of the new agent were estimated as follows: 4000 hours through avoidance of INR-related delays, 400 hours through elimination of delayed discharge counseling, 284 hours in reduced time to administer discharge counseling. Total patient days saved by the new drug were 142 per year, translating to $213,000 in revenue opportunity by improving the efficiency of the discharge process. Additional drug costs to the facility were estimated to be $19,776 assuming drug prices and patient volume are consistent with model inputs. CONCLUSIONS:  The model quantifies the system-level impact of new oral antithrombotics and informs formulary decision making.