Can I claim them?

Who is a Dependent?

According to the IRS, a dependent is a person who meets all five of the following criteria:

The person is a member of your household, or related to you.
You provide at least half of the person’s support.
The person’s gross income is less than $3,000.
The person must not have filed a joint return, except in certain circumstances.
The person must be a U.S. citizen or resident.
Basically, you can claim the person as a dependent if 1) the person is a relative and 2) you provided more than half of the person's support and 3) the person didn’t make too much money on his or her own.

But, because the IRS rules are incredibly complicated, you need to take a very detailed look at each of these tests, to make sure that the person really counts as a dependent. Remember: this is a Pass/Fail situation. If the person doesn't pass all these tests, the IRS will not allow you to claim him or her as a dependent.

The Person is a Member of Household or Related to You

To qualify as a dependent, the person must be a relative, or the person lived with you for the entire year. Note the or in that sentence.

Who’s a relative? The following count as relatives:

Your child, stepchild, adopted child, grandchild, or great-grandchild.
A foster child who lived in your home for the entire year, or a child placed with you by an authorized placement agency for legal adoption. However, if a state or tax-exempt child-placement agency makes payments to you as a foster parent, you may not claim the child as your dependent.
Your son-in-law or daughter-in-law.
Your parent, stepparent, parent-in-law, grandparent, or great-grandparent.
Your brother, sister, half brother, half sister, stepbrother, stepsister, brother-in-law, or sister-in-law.
Your aunt, uncle, nephew, or niece, if related by blood.
Anyone who lived in your home as a family member for the entire year meets this test, as long as the relationship does not violate local law.