Tracking cost basis for Backdoor Roth IRA

[kj6aqr]

I'm putting money in a post-tax ira and doing a yearly Roth conversion of the max amount.  Where is the cost basis tracked for this Roth IRA?  I see where to enter the cost basis for the Traditional IRA, and I assume that the cost basis is automatically tracked when I move it into the Roth, but I'm not seeing this on any of the tax return forms, etc.

[dmertz]

Basis in nondeductible traditional IRA contributions, Roth IRA contributions and Roth conversions is tracked by TurboTax on its IRA Information Worksheet.  Basis in Roth conversions is tracked by the year of the conversion until the conversion has met the 5-year holding period for the conversion to be equivalent to Roth IRA contribution basis, at which point all Roth conversions that have met the 5-year holding period are lumped together.  See Part V of the IRA Information Worksheet.