Sexual minority youths (i.e., those identifying as gay, lesbian, bisexual, or another nonheterosexual identity or reporting same-sex attraction or sexual partners) are at higher risk than youths who are not sexual minority youth (nonsexual minority youth) for negative health behaviors and outcomes, including human immunodeficiency virus (HIV) infection, other sexually transmitted diseases (STDs), pregnancy (1),* and related sexual risk behaviors (2). Less is known about sexual risk behavior differences between sexual minority youth subgroups. This is the first analysis of subgroup differences among sexual minority youths using nationally representative Youth Risk Behavior Survey (YRBS) data. CDC analyzed pooled data from the 2015 and 2017 cycles of the national YRBS, a cross-sectional, school-based survey assessing health behaviors among U.S. students in grades 9-12. Analyses examined differences in eight sexual risk behaviors between subgroups of sexual minority youths and nonsexual minority youths, as well as within sexual minority youths. Logistic regression models controlling for race/ethnicity and grade found that bisexual females and "not sure" males reported higher prevalences for many behaviors than did heterosexual students. For behavior-based subgroups, the largest number of differences were seen between students who had sexual contact with both sexes compared with students with only opposite-sex sexual contact. Findings highlight subgroup differences within sexual minority youths that could inform interventions to promote healthy behavior.