What if I was claimed as a dependent by a parent already

[Bsch4477]

If you were legitimately claimed as a dependent you must on your return check the box saying that you can be claimed by someone for else. 

[rjs]

If you meet the requirements for your parents to claim you as a dependent, then on your tax return you must check the box that says someone can claim you as a dependent. The question is whether they can claim you, not whether they actually do claim you. (If they can claim you, TurboTax will also ask whether they do claim you. That affects the education credits.) You can still file your own tax return.

If you do not meet the requirements for your parents to claim you as a dependent, but they claimed you anyway and they have already filed, then you will not be able to e-file. You will have to file your tax return by mail, without checking the box that says someone can claim you. You and your parents will then both get letters from the IRS asking for information to determine whether or not they are entitled to claim you.