Dear Brother and Brother,
In terms of social security's requirement, it depends on who evaluates and determines his qualifications. Let me give you an example of mine, an old client. Being on the deed, the person is considered as owning the place outright clean. The ownership affected the person's wealth, balance sheet, picture.
There is another example, the parent had the child on the deed which did not affect the child's disability benefit because the mortgage balance owed on the house was more than the value of the house.
So, my suggestion is not to put his name on the deed. It is not a positive move.
If your brother does not rent from you simply living with you, if he has no expenses, will he still qualify for his SSDI?
It seems that he is on disability than on pure social security. Social security is based on years of services and paid into the system and the age. Rental or ownership do not affect that qualification.
If he is on disability, having no expenses can and is likely to put him over the limit. You want to find out the consequence. It is possible that he is still qualified but for a lower amount. Then, that is not too bad and it is fare. As long as he is still qualified for medicaid. You want to go to SSA with him to make the inquiry.
I still think that working with your association should be the most positive, first move. And they probably will say that they don't care how much your brother reimburse you for your expenses or how you call it rent or whatever.
My general advice to my clients is that never own a real estate property with anyone other than your spouse.