The nationally representative 2008 American Religious Identification Survey found that 41% of self-identified atheists reported experiencing discrimination in the last 5 years due to their lack of religious identification. This mixed-method study explored the forms and frequency of discrimination reported by 796 self-identified atheists living in the United States. Participants reported experiencing different types of discrimination to varying degrees, including slander; coercion; social ostracism; denial of opportunities, goods, and services; and hate crime. Similar to other minority groups with concealable stigmatized identities, atheists who more strongly identified with their atheism, who were “out” about their atheism to more people, and who grew up with stricter familial religious expectations reported experiencing more frequent discrimination. Implications for future research tied to the ongoing religion/spirituality-health debate are discussed.