There are several qualifications for claiming an adult as a dependent:
1. You as the taxpayer must provide over 50 percent of your dependent’s living or support costs.
2. Your dependent must either live with you for 12 months or be your parent, grandparent, step-parent, aunt, or uncle.
3. Assuming the person does not have a disability, your dependent cannot have a gross income that exceeds the tax year’s exemption amount. The exemption amount in 2009 is $3,650.
4. Your dependent cannot file a joint return with another person for the year unless that tax filing is only completed in order to claim taxes that had been withheld.
5. Your dependent must be a US citizen, a US national, or a resident of the US, Canada, or Mexico.
A taxpayer may qualify for the Child and Dependent Care Credit if their dependent lives with them for more than 6 months of the year and have physical or mental issues that prevent them from caring for themselves. Visit the IRS website or consult Publication 503, Child and Dependent Care Expenses for further information.