I've hosted 3 exchange students 2016, two stayed for just a month and another stayed for 3 months. I did receive money to host as I provided food and utilities as well as housing. Do I claim this as an expense or income?
It depends- if the money you received was reimbursements for expenses you incurred (most likely) then you do not have income. If they paid you more than the value of what you provided it might be considered income. If you were not reimbursed for all of your expenses, you may be able to take a charitable contribution deduction if you itemize your deductions--
You may be able to deduct some expenses of having a student live with you. You can deduct qualifying expenses for a foreign or American student who:
Lives in your home under a written agreement between you and a qualified organization (defined later) as part of a program of the organization to provide educational opportunities for the student,
Isn't your relative (defined later) or dependent (also defined later), and
Is a full-time student in the twelfth or any lower grade at a school in the United States.
You can deduct up to $50 a month for each full calendar month the student lives with you. Any month when conditions (1) through (3) are met for 15 or more days counts as a full month.