To accommodate TurboTax's limitations in regard to handling a split rollover, the Form 1099-R must be split into two, one for the portion rolled over to the Roth IRA and the other fro the portion rolled over to the traditional IRA. The one for the portion rolled over to the Roth IRA will have the amount from box 5 in boxes 1 and 5 and the one for the portion rolled over to the traditional IRA will have in box 1 the original box 1 amount minus the box 5 amount.
As DavidD66 said, nothing about this goes on Form 8606. When entering the split form for the portion rolled over to the Roth IRA and indicating that it was rolled over to a Roth IRA, TurboTax will add this amount to your Roth IRA contribution basis shown on the IRA Information Worksheet. Form the split form for the portion rolled over to the traditional IRA, just answer No to both questions that ask if it was rolled over to some type of Roth account.
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