For some reason, some Roth IRA custodial banks do not provide any information in the 1099 form except for the gross distribution. You can call them and ask for a final statement or figure out your post tax deposits from your own records. That information will be input into a question about nondeductible contributions, after the natural disaster questions, in the TurboTax queries after you fill out the 1099 form which will then show up in section 3 of the 8606 form. This obscure, convoluted requirement is ridiculous and I don't know why banks issuing the 1099-R forms are not required to provide taxable amounts.
