If you had basis in nondeductible traditional IRA contributions and need Form 8606 included with your tax return to calculate the taxable amount of your Roth conversion, TurboTax will ask for your year-end balance in traditional IRAs which TurboTax might indicate is reported in box 5 of the Form 5498 from the traditional IRA. However, Form 5498 are not required to be sent until May, too late to be useful in preparing your tax return, so if you need your year-end balance in traditional IRAs you'll need to get it from your account statements.
Similarly, TurboTax might suggest that your contributions for the year that need to be entered into TurboTax are shown on Forms 5498, but again, since Forms 5498 are often not sent until May you need to simply enter the amounts of your contributions based on your own records.
