Thank you for your question. If your son is a qualifying child based upon the IRS tests, you can claim him even if he wants to claim himself.
In order to be a “qualifying child”, seven tests must be passed.
1) You cannot be a dependent of another taxpayer.
2) The child can not file a joint tax return with another taxpayer.
3) The child must be a US citizen, a US national or a resident of the US.
4) Relationship test- The child must be your son, daughter, stepchild, foster child, or a descendant of such.
5) Member of household test-The child must have lived in your home over half of the year with exception to temporary absence away from home.
6) Age test-The child must be under age 19 at the end of the year or under 24 and a full time student for at least any part of 5 calendar months during the year. There is no age requirement if the child is permanently and totally disabled.
7) Support test- The child can not provide over half of his/her own support.If he is a full time student. there are education credits that go with the exemption. If you claim him, you may be eligible for those credits. Please let me know if you need additional clarification. I look forward to your response. Stephanie