I'm single,age 54
I have a son, who turned 18 in sept. of 2007 and lives with me, he is Mildy Retared and gets SSI.
Does he have to file by his self? And I file myself?
Or
Do I claim him on my taxes? Begin that he get a disabiliy check each mo. (SSI)

If you provide HALF of his support and he does not EARN a salary (the SSI does NOT count as earned salary, nor is it factored into the support question), then you can claim him because he IS your child and he does NOT earn more than $3,400 for 2007.

You should also file as head of household
Internal Revenue Service

Example 1—child.

Your unmarried son lived with you all year and was 18 years old at the end of the year. He did not provide more than half of his own support and does not meet the tests to be a qualifying child of anyone else. As a result, he is your qualifying child (see Qualifying Child, later) and, because he is single, is a qualifying person for you to claim head of household filing status.

Agreed!