In response to severe measles, the first measles vaccine was licensed in the United States in 1963. Widespread use of measles vaccines for more than 50 years has significantly reduced global measles morbidity and mortality. However, measles virus continues to circulate, causing infection, illness, and an estimated 400 deaths worldwide each day. Measles is preventable by vaccine, and humans are the only reservoir. Clinicians should promote and provide on-time vaccination for all patients and keep measles in their differential diagnosis of febrile rash illness for rapid case detection, confirmation of measles infection, isolation, treatment, and appropriate public health response.