Taxpayers can claim low-income family members over age 65 as dependents if the taxpayers provide more than half of the elderly person's financial support each year, according to the Internal Revenue Service. Older family members who are dependents cannot earn more than $3,950, as of 2015.
The limit on earned income usually doesn't include Social Security benefits, notes TurboTax. When calculating how much support they provide older family members, taxpayers can count the value of room, board and living expenses. Taxpayers who claim elderly family members as dependents also can deduct qualified medical expenses, and they may be eligible for the dependent care tax credit.