GAO released an analysis on January 11 of Earned Income Tax Credit (EITC) eligibility and participation rates. The study estimates that one fourth of all eligible households do not claim the EITC. However, GAO's study was based on information from two mismatched databases and its conclusions should be taken with a large grain of salt. Given that caveat, the study confirms earlier findings that the participation rate is high - at least 86 percent among families with children. The study's findings do suggest that outreach to raise participation among very low-income households without children may be in order.