ObjectiveTo assess the relationship between the presence and generosity of state‐level Earned Income Tax Credits (EITC) and multiple self‐reported measures of general health.Data SourcesData on state‐level tax credits and covariates were obtained from the National Bureau of Economic Research and University of Kentucky Center for Poverty Research, respectively. These data were merged with Behavioral Risk Factor Surveillance System survey records from 1993‐2016.Study DesignUsing difference‐in‐differences approaches and survey‐weighted Poisson regression that accounted for clustering of observations and included state and year fixed‐effects, we assessed relationships between EITC and self‐reported overall health, frequent mental distress, and frequent poor physical health in the prior 30 days. Covariates included state minimum wage, state GDP, and adoption of Medicaid expansion. Sensitivity analyses revealed that parallel trends were plausible; there were no significant lead and lag effects.Data Extraction MethodsAnalyses were restricted to respondents with no more than a high school diploma or equivalent because less‐educated adults are more likely to be low‐wage earners and therefore qualify for EITC.Principal FindingsAmong adults with no education beyond high school (n = 2 884 790), each additional 10‐percentage‐point increase in the generosity of state EITC—relative to the federal credit—was associated with fewer reports of frequent mental distress (−97.3 per 100 000; 95% CI: −237.2, 42.6) and frequent poor physical health (−149.6 per 100 000; 95% CI: −284.4, −14.9). When restricted to individuals interviewed during the three months when tax rebates are commonly disbursed, the magnitude of the association between EITC and prevalence of reported frequent mental distress was greater (−329.7 per 100 000; 95% CI: −636.0, −23.5).ConclusionsThe generosity of state EITC policies is positively associated with significant reductions in frequent mental distress and poor physical health, especially during months when the credit is received. Interventions to reduce poverty may positively impact health by reducing material hardship and stress.