The aim of our study was to assess hospital budget implications of substituting dabigatran for warfarin in patients enrolled in a large anticoagulation service. The study population was identified using criteria from randomized controlled trials of dabigatran. We obtained labor costs ($483 per patient) from the hospital's anticoagulation service budget, laboratory costs of international normalized ratio (INR) tests ($267 per patient), and wholesale costs of warfarin 5 mg tablets ($31 per patient) and dabigatran 150 mg capsules ($2464 per patient). A total of 1774 (93.5%) of 1898 patients were eligible to substitute dabigatran for warfarin. The annual projected hospital expense for anticoagulation with dabigatran was $4,371,136, attributable to drug cost alone. The annual projected cost of warfarin management was $1,385,494. This was comprised of $856,842 for labor, $473,658 for INR testing, and $54,994 for the drug cost of warfarin. Substitution will result in increased expense due to drug cost.