If for any reason you withdraw money from the Roth IRA before age 59-1/2, you will need to know your amount of contributions, because it will determine if the withdrawal is taxable.
Your Roth IRA balance is divided into 3 classifications:
1. Direct contributions.
2. Rollovers or conversions.
3. Earnings.
You don't need to know your previous contributions to calculate the tax on the rollover, but Turbotax wants to know so it can keep track for you for the future. Now is as good a time as any to go back into the records of your account and document all your contributions and previous conversions. The Roth IRA custodian should be sending you a form 5498 each year documenting your contributions, or you can assemble bank records and so on.
