The sexual health of transmen--individuals born or assigned female at birth and who identify as male--remains understudied. Given the increasing rates of HIV and sexually transmitted diseases (STDs) among gay and bisexual men in the United States, understanding the sexual practices of transmen who have sex with men (TMSM) may be particularly important to promote sexual health or develop focused HIV prevention interventions. Between May and September 2009, 16 transmen who reported sexual behavior with nontransgender men completed a qualitative interview and a brief interviewer-administered survey. Interviews were conducted until redundancy in responses was achieved. Participants (mean age, 32.5, standard deviation [SD] = 11.1; 87.5% white; 75.0% "queer") perceived themselves at moderately high risk for HIV and STDs, although 43.8% reported unprotected sex with an unknown HIV serostatus nontransgender male partner in the past 12 months. The majority (62.5%) had used the Internet to meet sexual partners and "hook-up" with an anonymous nontransgender male sex partner in the past year. A lifetime STD history was reported by 37.5%; 25.0% had not been tested for HIV in the prior 2 years; 31.1% had not received gynecological care (including STD screening) in the prior 12 months. Integrating sexual health information "by and for" transgender men into other healthcare services, involving peer support, addressing mood and psychological wellbeing such as depression and anxiety, Internet-delivered information for transmen and their sexual partners, and training for health care providers were seen as important aspects of HIV and STD prevention intervention design and delivery for this population. "Embodied scripting" is proposed as a theoretical framework to understand sexual health among transgender populations and examining transgender sexual health from a life course perspective is suggested.