Generally, you may claim a parent as a qualifying relative dependent if the following are true:

1. The parent is not a qualifying child of any other taxpayer.
2. Your parent is your biological parent, stepmother or stepfather, or father-in-law or mother-in-law (not a foster parent)
3. Your parent's gross income is less than $4,200
4. You provide more than half of a person's total support during the calendar year.

For more information refer to IRS Publication 501 Dependents, Standard Deduction, and Filing Information. You may also wish to utilize the IRS Interactive Tax Assistant (ITA) topic Who can I claim as a dependent?