OBJECTIVES: This study examined the health insurance status of the US foreign-born population and the influence of race, ethnicity, and length of residence on health insurance status. METHODS: Data were obtained from the 1989 and 1990 National Health Interview Surveys, including the Insurance and Family Resource Supplements. RESULTS: In 1989 and 1990, the foreign-born population was twice as likely as the US-born population to be uninsured (26.2% vs 13.0%). The highest rate of uninsured status, 40.8%, was found among foreign-born Hispanics. Persons who had lived in the United States for less than 15 years were 1.5 to 4.7 times more likely to be uninsured than were US-born Whites. CONCLUSIONS: Foreign-born US residents-especially Hispanics and persons residing in the United States for less than 15 years-are vulnerable to not having health insurance, which may limit their access to medical services. The administrative criteria for public programs may explain the high rates of uninsured status among recent immigrants. Recently enacted federal legislation could substantially increase the number of uninsured among the US foreign-born population, with profound public health implications.