Yes, assuming that your son lives with you most of the year, and your son’s father is claiming him as a dependent under an agreement between you or because your signed form 8332 to release the exemption for him.

If the father is not the custodial parent (your son lives with you for more than half of the year) you are entitled to claim head of household filing status (if eligible) the earned income tax credit, the health coverage tax credit and child and dependent care expense credits.

He can claim the exemption and the child tax credit for 1,000 dollars. See IRS Publication 501 for more information dependency issues by clicking here.