Once the MCC (Mortgage Credit Certificate) and Mortgage Interest is entered into TurboTax at the full amounts the program will reduce the deductible mortgage interest by the amount of the non-refundable MCC.
The adjustments are automatic. It does not appear to matter which order you put them in. Either the Mortgage interest first or the MCC first as long as they are both entered.
If you need specific directions on how to enter either of them, please comment and I will gladly add the directions with screenshots to this answer.
