I don't believe that we have any basis in nondeductible traditional IRA contributions. In other words, all traditional IRA contributions spouse & I have made over the years have been deductible. Right now the TurboTax IRA Information Worksheet looks like this:
Part I Traditional IRA section -- shows no amounts for taxpayer and spouse
Part II Roth IRA -- has the proper amounts. (I recently updated according to advice from danab27 on how to do so since I hadn't distinguished Roth conversions from Traditional withdrawals one year. https://ttlc.intuit.com/community/taxes/discussion/re-ira-information-worksheet-i-didn-t-enter-roth-...)
Part III Traditional IRA Basis Detail -- shows no amounts.
Part IV Traditional IRA Year-end Value Detail -- shows no amounts.
Part V Roth IRA Contribution and Conversion Balances -- shows proper amounts.
Part VI Roth IRA Basis Adjustments -- shows no amounts.
In an external spreadsheet I have painstakingly documented all Traditional contributions and all Roth contributions and conversions. I am satisfied that The TurboTax IRA Information Worksheet, at this point, now has the accurate Roth amounts listed. Nothing is listed for Traditional Basis. Therefore I believe all of our IRA information is correctly documented, since all Traditional IRA contributions have been deductible. Does that sound correct?