Making Work Pay Credit. This form is used for taxpayers who are not claimed as a dependent by another taxpayer, those who are not a nonresident alien and have a valid Social Security number, or those who have received an earned income - although the maximum credit is reached at $6,451 for individual taxpayers and $12,903 for those who are married and filing jointly. This credit equals 6.2 percent of an individual's earned income, with a maximum of $400 for individual taxpayers, and a maximum of $800 for married couples who file jointly. Married couples are eligible for the credit, even if only one spouse works.