I did efile, and they said my return was not accepted because "This taxpayer or taxpayer's spouse has been claimed as a dependent on someone else's return (according to returns the IRS has already received). Make sure that no other person can claim this taxpayer or spouse as a dependent (for example, the parents or grandparents), and that the dependent's Social Security number has not been used on another return as the primary or secondary taxpayer's SSN (the persons listed first and second on the return).