Sexual behaviors of adolescent emerging and young adult men who have sex with men ages 13-29 in New York City.

Content: HIV infections among young men who have sex with men (YMSM), ages 13-29 in New York City have been steadily increasing over the last decade.

Objective: To document the sexual onset and behavior of YMSM as a means for informing the development of new HIV prevention messaging.

Design: Cross-sectional study.