The Earned Income Tax Credit (EITC) is the largest poverty alleviation program for families with children in the US, and it has well-documented health effects. However, not all eligible families receive benefits. The Assessing California Communities' Experiences with Safety Net Supports (ACCESS) Study interviewed 411 EITC-eligible Californians with young children to understand low take-up of the federal EITC and California's supplemental CalEITC. Interviews were conducted in English and Spanish in 2020 and 2021 to gather information on sociodemographic characteristics, tax filing, and EITC receipt (verified via tax forms). Among those eligible for the EITC or CalEITC, 9 percent of participants did not file taxes; among those who did file taxes, about 84 percent received the EITC, and 83 percent received the CalEITC. Lower likelihood of federal EITC receipt among those eligible and filing taxes was associated with being younger, not speaking English, and not having prior knowledge of the EITC. Lower likelihood of CalEITC receipt among those eligible and filing taxes was associated with not speaking English. These findings can inform policies and community interventions to increase EITC take-up and thereby help address health equity.