The EITC (Earned Income Tax Credit) is a "refundable tax credit" ("unconditional money") one can receive after a filing a tax return.
Generally, the EITC is meant to help low income folks who have earnings from a job or self employment.
In this case, (Eva Vellai-Palotay vs. The United States, Ct. of Fed. Claims), a woman who was receiving Social Security disability income sought an EITC tax refund on the basis of her disability income.