The Patient Protection and Affordable Care Act of 2010 (ACA) restricts its health insurance expansions in ways that exclude many uninsured children in California who are immigrants or have immigrant parents. These exclusions directly limit coverage options for noncitizen children. And immigrant parents, potentially misinterpreting eligibility requirements for these new programs, may not enroll their citizen children. Using the 2007 California Health Interview Survey (CHIS 2007), this policy brief estimates that of the 1.08 million children in California who were uninsured all or part of the year, between 180,000 to 220,000 will be excluded from the health care reform expansions due to the combined direct and potential indirect effects of these exclusions. This "left-out" group comprises between 17% and 20% of all uninsured children in California. In light of these exclusions, California’s community clinics and public hospitals could continue to serve a significant number of uninsured immigrant children even after full implementation of ACA.