Mortgage Recast vs. Extra Payments vs. Refinance

Say you are five years into a $400,000 mortgage at 6.5%. Your balance is $374,443.91 and your payment is $2,528.27. A $50,000 windfall lands — a bonus, an inheritance, a home sale. You have three ways to point it at the mortgage, and they do completely different things:

• Recast: lower your monthly payment, keep your rate and payoff date.
• Extra payment: keep your payment, pay the loan off years early.
• Refinance: lower your rate (and payment), but reset the clock.

They are not interchangeable. Picking the right one depends entirely on what you are trying to accomplish. Here are the exact numbers from the calculator, then a simple way to choose.

The three options, side by side

Same starting point: $374,443.91 balance, 25 years left, 6.5% rate, $2,528.27 payment.

Option            What you do                  New payment   Effect
Recast            $50k to principal,           $2,190.67     Payment drops $337.60/mo;
                  loan re-amortized                          same payoff date, same 6.5%
Extra payment     $50k to principal,           $2,528.27     Saves $152,577.44 interest;
                  payment unchanged                          paid off 6 yrs 8 mos early
Refinance         New loan at 5.5%,            $2,126.05     Payment drops $402.22/mo;
                  30-yr term, $6k costs                      break-even at month 15

Three different outcomes from the same $50,000. Let us walk through each.

Recast: lower the payment, keep everything else

A recast (also called re-amortization) is the least-known option and often the most useful. You make a large lump-sum principal payment, and the servicer recalculates your monthly payment over the remaining term at your existing rate. Your $374,443.91 balance becomes $324,443.91, re-amortized over the same 25 years, and the payment falls from $2,528.27 to $2,190.67 — $337.60 a month back in your pocket.

What you keep: your interest rate (critical if today's rates are higher than your loan), your payoff date, and most of your loan's amortization progress. What it costs: a small servicer fee, typically $150–$500 — not the thousands a refinance runs.

Recast is the right move when you want to lower required cash flow without giving up a good rate. The catch: it does not save much interest compared to just paying extra, because you are stretching the smaller balance back over the full remaining term.

Extra payment: kill the loan, save the most interest

The simplest option: drop the $50,000 on principal and keep paying $2,528.27. Your payment does not change, but because the balance just fell by $50k, the loan ends 6 years and 8 months early and you avoid $152,577.44 in interest.

This is the winner if your goal is to pay the least total interest and own the home free and clear sooner. It is also the most flexible — you did not sign any paperwork, change any terms, or pay any fee. The trade-off versus a recast is that your monthly obligation stays high; the $50k is working to shorten the loan, not to ease your budget.

For the full math on extra payments of every size, see How Much Do You Save by Paying Extra on Your Mortgage?.

Refinance: lower the rate, but mind the reset

If rates have dropped since you closed, refinancing replaces your loan with a new one at the lower rate. Refinancing the $374,443.91 balance to 5.5% on a new 30-year term cuts the payment to $2,126.05 — $402.22 a month less — and with $6,000 in closing costs, the break-even is month 15. After that, the monthly savings are pure gain for as long as you keep the loan.

The asterisk: a new 30-year term re-extends the clock. You were 25 years from payoff; a fresh 30-year loan pushes that back to 30. The lower rate still usually wins on monthly cost, but if you refinance, consider a shorter term (or keep paying your old higher payment) so you do not trade a lower rate for decades of extra interest. The full break-even framework is in Refinance Break-Even: When Refinancing Actually Makes Sense.

How to choose

Match the tool to the goal:

• "I need lower monthly payments and I have a good rate I want to keep." → Recast. Lower payment, no refinance costs, rate untouched.
• "I want to pay the least interest and own the house sooner." → Extra payment. Most interest saved, total flexibility, zero cost.
• "My rate is well above today's market." → Refinance. The rate cut can beat everything else — but watch the term reset, and confirm you will stay past the break-even.

A useful combination: refinance to capture a lower rate and keep making your old, higher payment. You get the rate cut and an accelerated payoff at the same time.

Not every servicer offers recasts, and some loan types (many government-backed loans) do not allow them — call and ask before counting on it.

The bottom line

A recast lowers your payment while preserving your rate and payoff date for a small fee. An extra payment keeps your payment but saves the most interest and ends the loan years early at no cost. A refinance lowers your rate and payment but resets the term and costs thousands up front. On a $374k balance, the same $50,000 buys $337.60/month of cash-flow relief, $152,577.44 of interest savings, or $402.22/month of rate savings — depending on which lever you pull.

Model your own balance and windfall on the calculator and the refinance calculator to see which fits your goal.