The part B is calculated by the program (not an estimate, but a calculation based on income from the last two years just like it is really calculated). So part B premiums are accurate, though you to have the option in Assumptions to indicate the real rate of increase on that over the years if you feel its cost is going to go up fast than inflation.

Part A is included with your SS benefit, so there's nothing to calculate there.

Part D is an add on and you can show payments for that as a series of special expenditures if you like.

Part C is also an add on like D, so you'd indicate those payments as a series of special expenses.