If he has access to your w-2, there's no way to prevent him from misfiling. if you import your w-2, you can probably change the user-id and password on the account. if it's mailed to you, make sure the address is your current one. Contact your employer if need be. E-file as soon as possible because if you file first, this will prevent him from filing a joint return (the only filing status that would allow him to include your w-2). If he files a joint return first, you won't be able to e-file. it will have to be mailed and you may have to wait quite a while if you are due a refund.
