The refundable Child Tax Credit (CTC) offers an economic lifeline to low-income families that translates directly into the well-being of their children. Research shows that an increase of as little as $1,000 in family income has been shown to improve children’s test scores. This fact sheet examines the CTC’s value to more than 2 million U.S. citizen children living in low-income families with at least one undocumented immigrant parent.