His SSA-1099 has nothing at all to do with your tax return. You do not report his SS income on your tax return because it's not considered your income. if that's his only income, it doesn't get reported anywhere because it's not taxable.
At this link, you can find a Worksheet, number 3-1 and look at how support is determined. It would be very unlikely that he received enough income to provide half his support, given that he's not paying for his home , utilities, or any other similar costs of living. If he uses the money just for entertainment or savings, that's not support.
https://www.irs.gov/publications/p17/ch03.html#en_US_2016_publink1000170907
