Men who have sex with men (MSM) face a disproportionate share of the HIV epidemic throughout the world (Baral et al. 2007; Cáceres et al. 2008), and in low- and middle-income countries bear a greater burden of the epidemic relative to the general population. In many countries, the HIV risk to MSM is exacerbated by social, cultural, and political factors. These include cultural biases against MSM, limited access to information and services, low national investments in health, and legal, institutional, or social barriers, including negative bias among providers, that make it difficult for MSM to negotiate safe sex or obtain adequate services for preventing and treating HIV and other sexually transmitted infections (STIs). This situation is compounded by adverse human rights environments— for example, in settings where same-gender sexual relationships are illegal—where MSM may fail to seek treatment because doing so may lead to harassment, refusal of services, arrest, or violence.