Health literacy is important for all adults. Because lower health literacy is associated with lower educational attainment, many adult basic and literacy education programs increasingly provide health education to low-literate adults to improve their health literacy. Using data from the 2003 National Assessment of Adult Literacy (NAAL), this study examined the health literacy of adults across GED [General Educational Development] credential recipients, high school graduates, and non-high school graduates by various demographic and socioeconomic characteristics. Specific populations with lower health literacy levels were identified so that adult education entities and policy makers can target these groups with more support, funding, and better programs to improve their health literacy skills. (Contains 10 figures and 1 table.)