You are correct that the deferred compensation is supposed to be included in box 1 of your W-2. The best solution is to get a corrected W-2 from the employer. You might want to first review your calculations with the payroll department to make sure that the W-2 is really wrong.
If the employer will not correct the W-2, you can use a substitute W-2, Form 4852, to enter the correct information in your tax return. When you enter the W-2 in TurboTax, enter the correct amount in box 1 instead of the amount that's on the W-2. Then, on the "uncommon situations" screen, check the box for "Didn't get a W-2" (even though that's not your situation). Do not check the box for "Nonqualified pension plan." The next screen will ask if you want to complete Form 4852. Select Yes. Proceed through the screens, entering the requested information to complete Form 4852. It will ask you to enter explanations of what you did to try to get a correct W-2 from your employer, and how you calculated the amounts that you entered. The prompts on most of the TurboTax screens assume that you didn't get a W-2 at all, but when you look at the form itself you will see that it is also used when you cannot get a corrected W-2 from your employer.
