Disabled Adult Child Do They Need To File Federal Return

[srobinet1]

My special needs adult son he is 39 receives Social Security Survivors Benefits from his dad.  He lived in a group home for many years and then moved home with me. He has never filed a Federal Tax return and I am wanting to know if he needs to file.  He has no earned income and receives around $22,500 a year from the Social Security. Our state does not tax Social Security income. I do not claim him as a dependent even though he lives with me. He does help with some of the household expenses every month .  

I guess I really have 2 questions. The second question is if I claimed him as a dependent would I report the money he pays me every month.  He is not in a lease agreement or no formal arrangement.  

[rjs]

If the Social Security benefits are your son's only income, he does not have to file a tax return unless he received advance premium tax credit for health insurance from the Marketplace ("Obamacare"), or he took money out of a Health Savings Account (HSA) or Medical Savings Account (MSA). If he did receive advance premium tax credit he should have gotten a Form 1095-A. If he took money out of an HSA or MSA he should have gotten a Form 1099-SA.

You do not report the household expenses that he pays for on your tax return, whether or not you claim him as a dependent.

[NCperson]

@srobinet1 why not claim him and file Head of Household?