Yes, you may be able to.
His Social Security payments count as support provided by him but if he did not provide over 50% of all his living expenses, you may be able to claim him. TurboTax will ask you a series of questions to see if you are able to claim him as a dependent. To prepare the IRS Worksheet for Determining Support, click on Worksheet for Determining Support - IRS.gov
The first line of the Support Worksheet is: Funds Belonging to the Person You Supported
1. Enter the total funds belonging to the person you supported, including income received (taxable
and nontaxable) and amounts borrowed during the year, plus the amount in savings and other
accounts at the beginning of the year .
The following are the requirements to claim a dependent: https://ttlc.intuit.com/replies/5187060
[Edited 2-7-18|9:30 am PST]
