BACKGROUND We compared access to health care, use of services, and health care experiences for Mexicans and other Latinos by citizenship and immigrant authorization status. METHODS We acquired data from the 2003 California Health Interview Survey, with 42,044 participants representative of noninstitutionalized households. Participants were differentiated by ethnicity/race, national origin, and citizenship/immigration authorization status. Outcome measures included having a usual source of care, problems in obtaining necessary care, use of physician and emergency department care, and 3 experiences with health care. Multivariate analyses measured the associations of citizenship/immigration authorization status with the outcome measures among foreign-born Mexicans and other Latinos vs their US-born counterparts. RESULTS In multivariate analyses, undocumented Mexicans had 1.6 fewer physician visits (P < .01); compared with US-born Mexicans; other undocumented Latinos had 2.1 fewer visits (P < .01) compared with their US-born counterparts. Both undocumented groups were less likely to report difficulty obtaining necessary health care than US-born Mexicans (odds ratio, 0.68; P < .01) and other US-born Latinos (odds ratio, 0.40; P < .01), respectively. Undocumented Mexicans were less likely to have a usual source of care (odds ratio, 0.70; P < .01) and were more likely to report negative experiences than US-born Mexicans (odds ratio, 1.93; P < .01). Findings were similar for other undocumented Latinos, with the exception of having a usual source of care. Patterns of access to and use of health care services tended to improve with changing legal status. CONCLUSION In this large sample, undocumented Mexicans and other undocumented Latinos reported less use of health care services and poorer experiences with care compared with their US-born counterparts, after adjustment for confounders in multivariate analyses.