Then, no, you cannot claim him as a dependent. Someone who is not related to you cannot be claimed as a dependent unless they actually lived with you the whole year. So without even getting into the issue of his Medicare/Medicaid, you cannot claim him. It is kind that you are helping your friend, but it is not deductible in any way on your tax return.
IRS interview to help determine who can be claimed:
http://www.irs.gov/uac/Who-Can-I-Claim-as-a-Dependent%3F
https://ttlc.intuit.com/questions/3113432-who-can-i-claim-as-my-dependent
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
