Leprosy (Hansen’s disease) causes the most common treatable form of neuropathy in the world. Several endemic countries account for the majority of the world’s cases and most of the cases seen in the US are amongst immigrants. However, endemic cases of leprosy occur in the US. The pathogen is Mycobacterium leprae, a slow-growing, obligate intracellular pathogen that consistently infects skin and peripheral nerves. The clinical appearance of the skin and neurologic deficits develop months to years after infection and are determined by the host’s response to the infection. An individual’s disease classification can change over time based on the immune status of the individual. Immune-mediated “reactional states” may also occur that require additional recognition and treatment. Varied in its manifestations, a successful treatment approach relies on proper recognition and classification of disease.