Recalculation of a mortgage payment schedule using the remaining balance, rate, and term.
Reamortization is the recalculation of a mortgage’s payment schedule using updated loan inputs, usually the current principal balance, interest rate, and remaining term.
It changes how the existing or modified balance is scheduled to be repaid. Reamortization does not necessarily create a new loan.
Borrowers often assume that reducing principal automatically lowers the required monthly payment. On many mortgages, an extra principal payment shortens the payoff path and reduces future interest, but the scheduled payment remains unchanged unless the servicer performs an approved recast or another event requires recalculation.
Reamortization also explains payment changes after an adjustable-rate reset, modification, or end of an interest-only period. The balance, rate, and time left can be different from the inputs used to calculate the earlier payment.
| Input | Borrower-facing meaning |
|---|---|
| Current principal balance | Amount that remains to be scheduled for repayment |
| Current interest rate | Rate used to calculate interest under the loan terms |
| Remaining term | Number of payments left before maturity |
| Payment frequency | Monthly or other interval required by the loan |
| Loan feature | Fixed, adjustable, interest-only, modification, or other structure affecting calculation |
Escrow for taxes and insurance is generally separate from the principal-and-interest reamortization. A lower loan-core payment can therefore be offset by a higher escrow requirement.
| Event | Why a new schedule may be calculated |
|---|---|
| Mortgage Recast | Large principal reduction is spread over the existing remaining term |
| Adjustable-rate change | Updated rate is applied to the balance and remaining term under the note |
| Loan Modification | Approved changes to rate, balance, or term require a new payment schedule |
| End of interest-only period | Principal must begin amortizing over the time left |
| Negative-amortization recast | Increased balance must be repaid under the loan’s recast rules |
| Principal curtailment | May support a recast if the loan and servicer permit it; otherwise payment can stay unchanged |
The triggering event and loan documents determine whether reamortization is automatic, optional, or unavailable.
A borrower has a $280,000 balance, a fixed rate, and 24 years remaining. The borrower makes a $60,000 principal curtailment and receives approval for a mortgage recast.
The servicer reamortizes the new $220,000 balance over the existing 24-year remaining term at the existing fixed rate. The required principal-and-interest payment falls, but the interest rate and maturity date generally remain unchanged.
If the borrower had made the same principal payment without an approved recast, the balance and future interest would still fall, but the scheduled payment might remain the same and the loan would instead pay off earlier.
| Term | Existing loan retained? | Rate changed? | Maturity changed? |
|---|---|---|---|
| Reamortization | Usually yes | Only if the triggering loan event changes it | Not necessarily |
| Mortgage Recast | Yes | Usually no | Usually no |
| Loan Modification | Yes | May change | May change |
| Refinance | No; old loan is paid off | New loan has new terms | New loan has a new maturity |
| Extra principal payment alone | Yes | No | Contractual maturity stays, but payoff may occur earlier |
Reamortization is the calculation process. Recast or modification is the account event or agreement that can authorize the new schedule.
Suppose an ARM reaches an adjustment date with $245,000 outstanding and 27 years remaining. If the note rate changes under the index, margin, and cap rules, the servicer may reamortize the balance using the adjusted rate and time left. The required payment changes even though the borrower made no large principal payment.
That payment recalculation is not a refinance. The original loan, lien, and maturity framework remain in place unless the contract or a later agreement says otherwise.
Amortization is the general process of paying principal down over time. Reamortization creates an updated schedule after the inputs change.
Amortization Schedule is the table or projection produced by the calculation. Reamortization is the act of recalculating it.
Principal Curtailment is an extra balance reduction. It can precede a recast, but it does not by itself guarantee that the required payment will change.