Roth IRA distributions, how do I ensure the amount I report is not reported as taxable income?

[jsmith2640]

Report income from Roth IRA (1099-R) distributions where the "Taxable amount not determined". There are no contributions to the account. It was converted in 1998 and on that years tax form 8606 100% of the conversion was reported as taxable (line 16) that year. When using Turbo Tax what question directs the filing to present this distribution coming from the original"cost basis" and not from any profit?

[macuser_22]

Enter a 1099-R here:

Federal Taxes,
Wages & Income
I’ll choose what I work on (if that screen comes up),
Retirement Plans & Social Security,
IRA, 401(k), Pension Plan Withdrawals (1099-R).

OR  Use the "Tools" menu (if online version under My Account) and then "Search Topics" for "1099-R" which will take you to the same place.

Be sure to choose which spouse the 1099-R is for if this is a joint tax return.
Be sure to pick the correct 1099-R type: Standard 1099-R, CSA-1099-R, CSF-1099-R, RRB-1099-R.

[NOTE: When you get to the "Your 1099-R Entries" screen where you can add another 1099-R, use "continue" to keep going as there are additional interview questions after that screen in most cases. You can always return as shown above.]

After the interview asks for prior year contributions it will ask about conversions.