For any mortgage on your currently owned Primary or Vacation home, you can simply enter an additional monthly payment amount (in either today's or nominal dollars) and a start year for the additional payment to begin. The additional payments will start in January of the start year and will continue until the mortgage is paid off.

Consider creating an alternative profile with the additional payments so you can more easily see the impact to your base plan vs. your current mortgage payments.

To model a lump sum payoff, you can enter the lump sum as a monthly amount. Any excess will be ignored once the mortgage is paid off. For example, to try out a lump sum payoff on your Primary Home:

  1. Create an alternative profile.
  2. If you don't have sufficient Regular Assets to cover the lump sum amount, you'll need to create a "special withdraw" from Retirement Accounts to provide enough funding. Say, for this example, $75,000 from your IRA or 401(k). If you have started smooth withdraws from retirement accounts, this $75,000 needs to be in addition to those.
  3. In the alternative profile, choose to modify the Primary Home, go to the mortgage in question, and use the Additional Monthly Payment field to pay off the balance. For example, if your mortgage balance is $75,123, you can make an additional monthly payment of $76,000 (the excess will be ignored).
  4. Set the year you want to pay off the mortgage.
  5. Run the comparison and you'll see in the alternative profile the house is paid off in the year you chose and the comparison of discretionary spending will show you the annual difference this change makes.