The purpose of this HAN Advisory is to notify public health departments and healthcare facilities about this measles outbreak and to provide guidance to healthcare providers. Healthcare providers should ensure that all of their patients are current on MMR (measles, mumps, and rubella) vaccine. They should consider measles in the differential diagnosis of patients with fever and rash and ask patients about recent international travel or travel to domestic venues frequented by international travelers. They should also ask patients about their history of measles exposures in their community. Measles is a highly contagious, acute viral illness. It begins with a prodrome of fever, cough, coryza (runny nose), conjunctivitis (pink eye), lasting 2-4 days prior to rash onset. Measles can cause severe health complications, including pneumonia, encephalitis, and death. Measles is transmitted by contact with an infected person through coughing and sneezing; infected people are contagious from 4 days before their rash starts through 4 days afterwards. After an infected person leaves a location, the virus remains viable for up to 2 hours on surfaces and in the air.