You may be able to claim your parents as dependents on your tax return if they meet the qualifications for "qualified relatives":

1. Not a qualifying child - Since they are your parents, they could not be a qualifying child.
2. Member of household or relationship test – Your parents don't necessarily have to live with you, but it's OK if they do.
3. Gross income test - To meet this test, a person's gross income for the year must be less than $4,050.  Gross income is all income in the form of money, property, and services that isn't exempt from tax.
4. Support test - To meet this test, you generally must provide more than half of a person's total support during the calendar year.  You figure whether you have provided more than half of a person's total support by comparing the amount you contributed to that person's support with the entire amount of support that person received from all sources. This includes support the person provided from his or her own funds.

Even if you can't claim your parents as dependenst because of their income, you could deduct medical expenses you paid for him.  IRS Pub. 502 states that "You can include medical expenses you paid for an individual that would have been your dependent except that: . . . "He or she received gross income of $4,050 or more in 2016."