Many men who have sex with men (MSM) do not disclose their same sex behaviors to healthcare providers (HCPs). We used a series of logistic regression models to explore a conceptual framework that first identified predictors of disclosure to HCPs among young MSM (YMSM), and subsequently examined young men's disclosure of male-male sexual behaviors to HCPs as a mediator between sociodemographic and behavioral factors and three distinct health outcomes [HIV testing, sexually transmitted infection (STI) testing, and human papillomavirus (HPV) vaccination]. We determined the predictors of disclosure to HCPs among YMSM and examined the relationship between disclosure and the receipt of appropriate healthcare services. Data were collected online through a US national sample of 1750 YMSM (ages 18-29 years) using a social and sexual networking website for MSM. Sexual history, STI/HIV screening history, sexual health, and patient-provider communication were analyzed in the logistic regression models. Participants were predominantly white (75.2%) and gay/homosexual (76.7%) with at least some college education (82.7%). Young men's disclosure of male-male sexual behaviors to HCPs was associated with the receipt of all healthcare outcomes in our model. Disclosure was a stronger mediator in HPV vaccination than in HIV and STI testing. Disclosure to non-HCP friends and family, HCP visit in the past year, and previous STI diagnosis were the strongest predictors of disclosure. Young men's disclosure of male-male sexual behaviors to HCPs is integral to the receipt of appropriate healthcare services among YMSM. HPV vaccination is more dependent on provider-level interaction with patients than HIV/STI testing.