"What is already known about this topic? Convenience samples indicate that transgender youths appear to be at higher risk for violence victimization, substance use, suicide risk, and sexual risk behaviors than are cisgender youth. What is added by this report? Population-based survey data from 10 state and nine urban school districts found that an average of 1.8% of high school students identify as transgender. Transgender students were more likely than were cisgender students to report violence victimization, substance use, and suicide risk, and, although generally more likely to report sexual risk behaviors, were also more likely to report having been tested for human immunodeficiency virus."