Certain taxpayers are eligible for a tax credit
If your adjusted gross income is less than $50,000, you may be eligible for a nonrefundable credit against your income tax for elective contributions you make to §401 (k) plans,
§403(b) annuities, §457 plans, SIMPLE or simplified employee pension (SEP) plans, traditional or Roth IRAs, and voluntary after-tax employee contributions to a qualified retirement plan or a 403(b) annuity.
The amount of your credit can be as much as 50%, 20%, or 10% of your contribution depending upon your filing status and modified adjusted gross income, giving you a maximum annual credit of $1,000 ($2,000 if married filing jointly).
This credit was due to expire at the end of 2006; however, recently enacted legislation made this credit permanent. After 2006, the adjusted gross income limits will be indexed for inflation, making more taxpayers eligible for the credit.