The situation you described is also known as a back door Roth contribution.
A back door Roth is a term used to describe a method of funding a Roth IRA when your modified adjusted gross income (MAGI) is too high to allow you to directly contribute to a Roth IRA. A back door Roth consists of opening a Traditional IRA and making a fully non-deductible contribution to the Traditional IRA. The Traditional IRA can then be converted to a Roth IRA without any income limitations or restrictions on your MAGI.
Here are the general steps you need to take to report this type of
transaction in TurboTax, either the online or desktop version. First, take care of the Traditional IRA contribution:
That takes care of the first part of the process. Next, you need to take care of the conversion of the Traditional IRA to the Roth IRA. When you do this, a Form 1099-R will be issued to report the conversion. You will simply enter the information from the Form 1099-R into TurboTax using these steps:
One more note, if the Traditional IRA earned any money before it was converted to the Roth IRA, those earnings will be taxable on your return.