Indicating the amount that is RMD has absolutely no effect on the amount that is taxable unless you rolled over some of the distribution, in which case TurboTax will properly treat as rolled over only the amount in excess of the amount that you indicate indicate is RMD. If you did not roll over any of the distribution, indicating that it is all RMD will not increase the taxable amount. The taxable amount for those over age 70½ is the same as for those under age 70½. Some states provide pension exclusions for those over age 65, but that has nothing to do with whether or not the distribution is an RMD.
