If you have them for 6 months out of the year & he does not & you can prove that they reside with you more than 6 months out of the year then I think you can file them on your taxes. IRS is not governed by a state Judge ruling. Because the IRS is governed by Federal laws. Now like I said you can only file them I think if you can prove they reside with you more than 6 mths out of the year. And provided you did not file a form 8332. Because a form 8332 if you sign it does give the other parent the right to file the kids. And the IRS under that exception of the form 8332 will let the other parent file the child on their taxes. And paying child support does not give the other parent the right to file a child/ children on their taxes. As far as him not exercising his visitation you may want to take him back to court on a show cause as to why he's not exercising those rights. A judge told my husband's ex wife that if she didnt exercise her rights she would lose them. My husband has full custody of their son so we can kinda relate to what you are going through. But please consider taking him back to court for not exercising his visitation rights. And to be sure about the tax thing contact the IRS & ask them for sure. They will tell you the answer to your question.But I do know what I stated earlier about having the kids for more than 6 mths out of the year. And about the 8332 form because we have been through a similar thing with my husband's ex wife. Hope this is helpful.