Tax benefits tied to children form a central component of the social safety net in the United States. To participate in these programs, taxpayers must claim a child on their tax return. We study the claiming of children on tax returns by drawing on health insurance information returns to establish the presence of children in the United States. We esti-mate that the vast majority of insured children (approximately 95 percent) and a significant majority (between 88 and 97 percent) of all U.S. children are claimed on tax returns. Un-claimed children are disproportionately concentrated in lower income households and are more likely to live in Black and Hispanic neighborhoods.