If your Traditional IRA distribution that was converted to a Roth IRA is showing as taxable on your return, then the basis (non-deductible contribution) of the Traditional IRA does not match the distribution amount.
Your income may allow you to claim a partially or fully deductible Traditional IRA contribution by default. If that is the case, TurboTax will choose this option because it would result in a better tax outcome without considering the Roth IRA conversion. Go back through the section of your return where you entered your Traditional IRA contribution and be sure that you indicate that you want to make the entire contribution non-deductible.
If this still does not work, please respond with more information about what you see reported on Form 1040 line 4a and 4b, along with the amount of contribution you made to the Traditional IRA and we will try to help you further.
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