The error won't be corrected through TurboTax. Your son will need to mail the amended return (1040X) and you will need to paper file and mail your return if you claim your son as your dependent. The exemption will not be freed-up any time soon by the IRS and it is doubtful that you will be able to e-file this season, even if you file an extension. You also have the option of e-filing without claiming him and then file your own amended return to claim his exemption. All amended returns must be paper-filed and mailed.
