Hansen disease, historically known as leprosy, is caused by Mycobacterium leprae. The disease is rare in the United States but remains endemic among certain immigrant populations, and may manifest years after infection. The US military has a number of active duty troops originally from endemic countries. Recently, three US soldiers with Hansen disease were evaluated at Walter Reed Army Medical Center. The mean time to diagnosis was 8 months (range, 2 to 18 months). All three patients were initially misdiagnosed and treated for other skin infections or contact dermatitis. These cases illustrate the importance of prompt recognition and treatment of Hansen disease to prevent permanent disability and disfigurement. The clinical presentation, diagnosis, classification, and currently recommended therapeutic regimens for Hansen disease are discussed.