During 2007–2010, 48% of U.S. women and 41.1% of U.S. men aged 18–59 years reported having ever been tested (outside of blood donations) for HIV infection. For both men and women, an increase in the number of lifetime sexual partners increased the likelihood that they were tested for HIV. Among persons with zero lifetime sex partners, men were more likely to have had HIV testing than women (24.9% compared with 13.2%). However, among persons with 2–4, 5–9, and 10 or more lifetime sex partners, women were more likely than men to have reported any HIV testing.