Sociological studies of atheism have tended to coalesce around three primary themes: stigma, identity, and community. To date, however, no studies have taken a reflexive approach to these themes or applied them in the field to test their analytical utility as well as their relations in contemporary atheist experi- ence. This study employs a mixed-methods approach that includes in-depth interviews (n = 19), partici- pant observation, and one survey administered to two atheist groups, one local (n = 151) and one national (n = 456). Ethnographic findings confirm the central role of stigma, identity, and community in atheist experience and emphasize their nestedness in one another. Survey results find that atheist affiliates in both national and local groups rate political activism as more important than social reasons in motivating them to affiliate, while local affiliates rated social reasons significantly higher than national affiliates rated social reasons. Suggestions for future research include consideration of these themes’ connectedness in subsequent analyses and further inquiry into the functional divergences between local and national athe- ist organizations.