Community health centers (CHCs) have long served an important safety-net healthcare delivery role for vulnerable populations. Federal efforts to expand CHCs, while potentially reducing the Federal budget for Medicaid, raise concern about how Medicaid and uninsured patients of CHCs will continue to fare. To examine the primary care experiences of uninsured and Medicaid CHC patients and compare their experiences with those of similar patients nationally, cross-sectional analyses of the 2002 CHC User Survey with comparison data from the 1998 and 2002 National Health Interview surveys were done. Self-reported measures of primary care access, longitudinality, and comprehensiveness of care among adults aged 18 to 64 years were used. Despite poorer health, CHCs were positively associated with better primary care experiences in comparison with similar patients nationally. Uninsured CHC patients were more likely than similar patients nationally to report a generalist physician visit in the past year (82% vs 68%, P < .001), having a regular source of care (96% vs 60%, P < .001), receiving a mammogram in the past 2 years (69% vs 49%, P < .001), and receiving counseling on exercise (68% vs 48%, P < .001). Similar results were found for CHC Medicaid patients versus Medicaid patients nationally. Even within CHCs, however, Medicaid patients tended to report better primary care experiences than the uninsured. Health centers appear to fill an important gap in primary care for Medicaid and uninsured patients. Nonetheless, this study suggests that Medicaid insurance remains fundamental to accessing high-quality primary care, even within CHCs.