Reamortize: What It Means for Your Mortgage (and 401(k) Loan)

You will meet the term in a few places: on a servicer's phone tree, in the title of Fannie Mae Form 181 (Agreement for Modification, Re-Amortization, or Extension of a Mortgage), in 401(k) plan paperwork, and in spreadsheet templates built by people who work in mortgage operations.

Take a borrower with a $300,000 balance at 6.5% and 25 years (300 months) left. They pay $50,000 toward principal and ask the servicer to reamortize.

With a typical $250 fee, the lower payment pays the fee back in under a month. Total interest over the remaining 25 years falls from about $307,700 to about $256,400, purely because there is less principal for interest to accrue on.

The same $50,000 can be used two ways, and the difference is large enough to decide on purpose.

Skipping the recast saves roughly $93,600 more in interest, but only if you keep paying the old amount. A popular middle path is to reamortize anyway and keep paying the old amount voluntarily: you pay off on the same fast schedule, but your required payment is $338 lower if money gets tight. The fee is the price of that safety net.

1. Ask your servicer if your loan is eligible. Ask for the minimum lump sum (commonly $5,000 to $10,000), the fee, and any payment-history requirement.
2. Send the lump sum as a principal payment. Make sure it is marked principal-only, not as an early installment.
3. Submit the reamortization (recast) request. Many servicers have a form; some want it with the payment.
4. Keep paying the old amount until the new payment shows on your statement. Processing usually takes 30 to 90 days.
5. Check the new payment against the mortgage recast calculator. It should equal new balance ÷ old balance × old payment.

Full eligibility rules by loan type are in mortgage recast requirements.

Reamortization runs the standard amortization formula a second time. Nothing new is introduced:

What changes between the first run and the second is only which numbers go in:

Because the rate and the number of remaining months are both held fixed, the payment moves in a straight line with the balance. Reduce the balance by 12.5% and the payment falls 12.5%. This linearity is a useful sanity check on any reamortization figure you are given: divide the new payment by the old, and it should match the ratio of the new balance to the old. If it doesn't, someone has changed the term.

Reamortization is not only a mortgage word. 401(k) and other retirement-plan loans can be reamortized too, and the "People also ask" question about it comes up often. It usually happens when:

• You change payment frequency. For example, after leaving your employer you switch from payroll deductions every two weeks to monthly payments.
• You want a longer repayment period. The plan can stretch the remaining term, but never past the legal maximum counted from the date the loan was issued: 5 years for a general-purpose loan, longer only for a loan used to buy a primary residence, if the plan allows.
• A payment was missed or suspended (for example during unpaid leave), and the remaining balance is respread.

Unlike a mortgage recast, a 401(k) loan reamortization generally cannot change the interest rate, and there is no lump sum involved. You request it through your plan administrator, usually on a loan reamortization form. To see the payment on your own loan, use the 401(k) loan payoff calculator.

If you have read anything from Fannie Mae or spoken to a servicing department, you have probably met the phrase principal curtailment. It is not a separate product or a different kind of payment. It is the industry's word for money applied to reduce your unpaid principal balance ahead of schedule.

Fannie Mae's Selling Guide defines it in exactly those terms: a principal curtailment is the application of funds used to reduce the unpaid principal balance of the mortgage loan (Selling Guide B2-1.5-05). The same topic notes that curtailments applied to reduce the monthly payment are permitted, which is the contractual basis for recasting.

The word curtail is doing honest work here — you are cutting short the life of the debt.

Recasting is the most common reason a mortgage gets reamortized, but it is not the only one. The word covers any mid-life recalculation of a payment schedule.

• After a loan modification. When a servicer changes the rate or term of a distressed loan, the resulting schedule is reamortized around the new terms. Fannie Mae's Form 181 covers modification, reamortization and extension in a single instrument for exactly this reason.
• After a payment deferral. Where missed payments are moved to the back of the loan as a non-interest-bearing balance, the remaining schedule is recalculated.
• Construction-to-permanent conversion. A construction loan that draws down over time is reamortized when it converts to a permanent mortgage with a fixed balance.
• Adjustable-rate resets. Every time an ARM adjusts, the payment is reamortized over the remaining term at the new rate. This one happens automatically, without any request from you — see the ARM calculator.
• Student loans and some business loans. Income-driven repayment recalculations are reamortizations in the same technical sense.

Only the first three involve you asking for anything. The ARM case is worth internalising, because it means an adjustable-rate borrower experiences reamortization on a schedule whether or not they know the word.

Reamortize, re-amortize and re amortize are the same word. American usage prefers the closed form reamortize; mortgage documents, including Fannie Mae Form 181, often use the hyphenated re-amortization. British usage is re-amortise.

The root is amortize, from the Latin admortire, "to kill off": an amortizing loan is gradually killed off by scheduled payments. To reamortize is to redo that schedule partway through. If you are searching your loan documents, search for the stem amorti to catch every spelling.

What does reamortize mean on a mortgage?

It means the lender recalculates your monthly principal and interest payment using your current balance, your existing interest rate, and the months remaining on your term. When you trigger it with a lump-sum payment, it is called a recast.

Is reamortizing the same as a recast?

A recast is the most common kind of reamortization. Reamortization is the broader term: it also covers payment recalculations after a loan modification, an ARM rate reset, or a 401(k) loan change. Every recast is a reamortization, but not every reamortization is a recast.

Is reamortization the same as refinancing?

No, and the difference matters. Reamortization keeps your existing loan — same note, same rate, same lender, no underwriting. Refinancing replaces the loan entirely with a new one at current market rates, with a full application and closing costs. Reamortization typically costs $150 to $500; refinancing typically costs 2% to 5% of the loan amount. Run both on your own loan with the mortgage recast calculator.

Does reamortizing hurt your credit?

No. There is no new application, no hard inquiry and no new account. The loan continues reporting as the same tradeline with the same origination date.

Can any loan be reamortized?

Not on request. Conventional mortgages backed by Fannie Mae or Freddie Mac generally permit it. FHA, VA and USDA loans do not. Most jumbo and portfolio loans are at the lender's discretion. Auto loans and personal loans almost never offer it. 401(k) loans can be reamortized under plan rules. See recast requirements and eligibility for the full picture.

What is a principal curtailment on a mortgage?

Funds applied to reduce your unpaid principal balance ahead of schedule — an extra payment aimed at principal rather than at your next installment. Fannie Mae's Selling Guide B2-1.5-05 defines it in those terms. It is the trigger for a recast, but it does not cause one on its own; you have to request the reamortization separately.