I already mailed in my federal tax return, how can I efile my state tax return without double submitting my federal taxes?

[VolvoGirl]

If you mailed federal you will also have to mail state.  You can only efile state if Federal was first efiled and accepted.

[Opus 17]

For security reasons, you can't e-file a state return unless you e-file a federal return at the same time.

What you are trying to do is mail your federal return, then e-file both a state and federal return at the same time, in the hope that the state e-file will go though while the federal e-file will be rejected as a duplicate.  (Or, that if it is accepted, the IRS will recognize it as a simple glitch and won't cause you any inconvenience over the double submission.)

So basically you are trying to trick Turbotax and the IRS into letting you do something that the system is designed to prevent.

I would not recommend trying this.  Turbotax won't take responsibility for anything bad that happens as a result.

(Even NY, which has an e-file requirement if you use software, waives the requirement if situations in the software prevent you from e-filing.  This would qualify.)