While the Patient Protection and Affordable Care Act (ACA), signed into law in 2010, expanded health insurance coverage to millions of Californians, it did not extend eligibility for coverage to undocumented U.S. residents. Federal policy prohibits the use of federal funds to provide Medicaid to undocumented individuals. In 2015, the state of California extended Medi-Cal (California's Medicaid program) to undocumented children using state funds, and policies to extend eligibility to undocumented adults have been proposed. This policy brief includes the latest data from the California Health Interview Survey (CHIS) on the health insurance, demographics, health status, and access to care of undocumented low-income Californians ages 19-64. The data indicate that the great majority of these undocumented adults are working, live in families with children, and report being relatively healthy. However, significant disparities exist in access to health care between this group and their documented counterparts. This overview of undocumented low-income adult residents of California provides insights into the implications of extending full-scope Medi-Cal eligibility to this population, who currently have very limited options for affordable health insurance coverage and experience access disparities.