The US Centers for Disease Control and Prevention (CDC) declared endemic measles eliminated in 2000, with rubella and congenital rubella syndrome eliminated in 2004.1 However, vaccine-preventable diseases (eg, diphtheria, pertussis, tetanus, measles, mumps, and rubella) are increasing, with some parents delaying or selectively immunizing their children and, at times, even opting out of having their child immunized. In 2014, the United States recorded a record number of measles cases—644 cases from 27 states, more than 3-fold higher than any previous year since 2000. As of February 6, 2015, the CDC has reported 121 measles cases in 17 states, mostly from an ongoing outbreak linked to an amusement park in Orange County, California. Most cases were unvaccinated (55%) or of unknown vaccination status (31%).2