Things get messy when you end up rolling over a distribution that was reported as an NUA distribution because the amount in box 2a does not reflect the actual taxable amount of the distribution and TurboTax doesn't have a good way to determine the true taxable amount. If the entire distribution is rolled over the taxable amount would be the gross distribution minus the amount in box 4. You would have to enter the Form 1099-R as if no NUA had been distributed and provide explanation with your tax return as to why the reporting differs from what is reported on your tax return. You could do this by entering a substitute Form 1099-R (Form 4852) so that TurboTax prompts you for the explanation or you could just prepare the explanation statement outside of TurboTax. Either way you would need to mail your tax return under these circumstances.
