I see. I incorrectly assumed that the part that didn't go to the traditional IRA went to a non-retirement account.
Under these circumstances I would expect the amount in box 2a to be zero. If it's not and the sum of the box 2a and box 5 amounts equal the box 1 amount, you apparently requested that the plan roll the entire amount over to a Roth IRA but then diverted part of it to a traditional IRA.
In this case you'll need to split the code G Form 1099-R into two to accommodate TurboTax's deficiency in dealing with this situation, one for the portion rolled over to the traditional IRA and the other for the portion rolled over to the Roth IRA. Assuming that the portion rolled over to the Roth IRA was at least as much as the amount in box 5 of this Form 1099-R, the entire box 5 amount will go on the form you enter for the portion that went to the Roth IRA and none of the box 5 amount will go on the other.
