Q. Can I claim him as a dependent?
A. No, because he makes decent money and files his own taxes. Supporting a person is only one of several dependent tests.
Q. I pay all the bills, mortgage, etc. Are there any deductions I can take?
A. There are no deductions you can take related to you allowing someone to live with you, rent free. As a home owner, you are allowed to deduct mortgage and property tax. These are itemized deductions. You can't (actually "shouldn't") deduct itemized deductions unless it's more than your standard deduction ($24,800 Married filing jointly)
