My son turned 18 yrs old Aug. 31, 2012, he moved out in early to mid Oct. My son received Social Security up til Aug 3rd 2012. He just filed his taxes and claimed himself. Since my son was on Social Security til he turned 18 and that he lived with us 9 months out of the year, don't I HAVE to claim him especially since he received Social Security?

“Since my son was on Social Security til he turned 18 and that he lived with us 9 months out of the year, don't I HAVE to claim him especially since he received Social Security?”================It depends on the situation; your son, as your dependent, can file his return. I mean despite your son files his return as your dependent, you can claim him as your dependent UNLESS he claims himself. However, once your son CLAIMED himself on his return as you said, then , you can’t claim him as your dependent on your return. For example, as long as your son has zero taxable income and he files his return just to receive all his federal income tax withheld as a refund, then, yo can file him on your return UNLESS he claimed himself and deducts $3.8K on his 2012 return.