If you are low-income, you may be eligible for the Earned Income Tax Credit (EITC). The EITC is a special credit to assist some working people. It can mean a refund for you or a reduction in the amount of income tax you pay.
More information is available in this brochure published by Legal Aid: The IRS may owe you money through the EITC.
This brochure is also available in Spanish at: El IRS puede Deberle Dinero a Través del Crédito por Ingreso Del Trabajo.