What is the difference between recasting and paying extra?

Both put the same lump against principal. A recast then re-amortizes the smaller balance over the same remaining term, so your payment falls and the payoff date stays put. Paying extra keeps your payment where it is, so the date moves earlier instead. Recasting costs a few hundred dollars; paying extra costs nothing.

Is recasting or paying extra cheaper?

Paying extra, always, at every rate and every balance. The two start identically and diverge immediately, because a recast reduces every subsequent payment while an extra payment leaves them all working against the balance. The calculator shows exactly what the recast costs, which is the price you pay for the lower monthly payment.

When should I recast instead?

When cash flow is the problem. A recast permanently lowers a fixed monthly obligation for a few hundred dollars, without the credit check, appraisal and thousands in closing costs a refinance needs. If your income has fallen or become less certain, that is worth more than the interest it costs.

Is refinancing better than recasting?

Only if the rate improvement is large enough to clear the closing costs. Refinancing is the only one of the three that changes your rate, so with a big enough drop it wins comfortably; with a small one the fees sink it. The refinance calculator works the breakeven out in detail, including how long you need to stay.

Can any mortgage be recast?

No. FHA, VA and USDA loans generally cannot be recast, and most conventional servicers require a minimum lump sum, a seasoned loan and a fee of $150 to $500. It is also entirely at the servicer’s discretion. Ask before planning around it, the option is less widely available than the arithmetic suggests.

Should the lump go at the mortgage at all?

A separate and often more important question. Paying a mortgage down earns a guaranteed return equal to its rate, which an investment has to beat after tax, mortgage payoff versus investing solves for that bar. If you hold higher-rate debt, clearing that first almost always wins.

Recast, Refinance or Pay Extra: Which Is Best?

Recast, refinance or pay extra: which is best for a lump sum against your mortgage? A recast lowers the payment and keeps the payoff date; paying extra keeps the payment and moves the date; refinancing changes the rate for a fee. This runs all three against each other.

Example numbers

The verdictfrom an example

Cheapest is pay the lump, keep the payment, at $212,541 of interest and fees. For the lowest payment instead, refinance frees $405.34 a month.

Worked on $320,000 at 6.80% with 25 years left, and a $40,000 lump sum. Change anything below to use yours.

Cheapest overall: Pay the lump, keep the payment
Lowest monthly payment: Refinance
Recast: $303,372

The figures behind it

Cheapest overall: Pay the lump, keep the payment; $212,541 of interest and fees, against $346,310 if you do nothing.
Lowest monthly payment: Refinance; $1,815.69 a month, freeing $405.34.
Recast: $303,372; $1,943.40 a month, still finishing in 25 years. The date never moves.
Pay the lump, keep the payment: $212,541; $2,221.03 a month, finishing 6 years, 6 months early. No fee at all.
Refinance: $264,704; $1,815.69 a month over 25 years, after $4,500 of costs.
Recast costs you: $90,830; Against simply paying the same lump and keeping your payment. That is the price of the lower payment.

What you still owe on each plan

Years from today

Do nothingRecastPay the lump, keep the paymentRefinance

Payment scheduleShow

The table scrolls sideways

Item	Do nothing	Recast	Pay extra	Refinance
Monthly payment	$2,221.03	$1,943.40	$2,221.03	$1,815.69
Months to clear	300	300	222	300
Interest paid	$346,310	$303,022	$212,541	$260,204
Fees	$0	$350	$0	$4,500
Total cost	$346,310	$303,372	$212,541	$264,704
Monthly cash freed	$0.00	$277.63	$0.00	$405.34

What this result assumes

A recast pays the lump to principal and re-amortizes the smaller balance over the same remaining term, so the payoff date does not move and the payment falls. Paying the same lump without recasting keeps the payment where it is and moves the date instead.
Those two start identically and diverge from the second month, which is why the extra payment always wins on interest and the recast always wins on cash flow. Neither is a mistake; they answer different needs.
The lump sum is excluded from every cost figure because it is spent under all three plans. What is compared is the interest and fees each option incurs afterwards.
Not every loan can be recast. FHA, VA and USDA loans generally cannot, most servicers require a minimum lump and a seasoned loan, and the fee varies, ask before assuming it is available.
Escrowed property tax and insurance are excluded. They are unchanged by all three options and would only add noise.

Methodology

Reviewed September 1, 2026

Three different things a lump sum can do

A recast pays the lump to principal and asks the servicer to re-amortize the smaller balance over the same remaining term. The payoff date does not move. The payment falls, permanently, for a fee of a few hundred dollars.

Paying extra puts exactly the same lump against exactly the same balance — and then carries on paying what you were paying. The payment does not move. The payoff date does, by years.

Refinancing replaces the loan entirely at a new rate and term, with closing costs to match. It is the only one of the three that changes the rate, and the only one whose costs run into thousands.

Why the recast always costs more, and is still not wrong

Recasting and paying extra begin identically: the same money reduces the same balance on the same day. They diverge in the second month, because a recast lowers every payment that follows while an extra payment leaves them all working at full size.

That makes the extra payment strictly cheaper in interest — always, at every rate and every balance — and it makes the recast strictly better for cash flow. The test suite asserts the first half of that directly. Neither is a mistake; they answer different questions, and the calculator reports what the recast costs so you can see the price of the lower payment rather than guess at it.

The practical read: if the reason for the lump sum is that money is tight, recast. If the reason is that you want the mortgage gone, pay extra and change nothing else.

Where refinancing fits

Refinancing is the only option that touches the rate, so it is the only one that can beat the other two by a wide margin — but only when the rate improvement is large enough to clear several thousand dollars of closing costs. Drop the refinance rate in the inputs and watch it overtake; raise it and watch the fee sink it.

The term is the other lever, and the trap. Refinancing to a longer term lowers the payment regardless of the rate, which flatters the comparison. Setting the refinance term equal to your remaining months isolates the rate effect, and is the default here for that reason.

The lump sum is deliberately left out of every cost figure. It is spent under all three plans, so including it would add the same number to each and change nothing. What is compared is the interest and fees each option incurs from that point on.

Assumptions

The lump sum is spent under all three options, so it is excluded from the cost comparison.
A recast re-amortizes the reduced balance over the original remaining term at the same rate.
Paying extra applies the lump to principal immediately and keeps the existing payment.
Refinance closing costs are rolled into the new loan.
All rates are fixed and payments level; no further overpayments are made.
Escrowed property tax and insurance are excluded — unchanged by all three.
Not every loan is eligible to recast; availability, minimum lump and fee are all servicer-specific.
The mortgage interest deduction is ignored, which slightly overstates the saving for filers who itemize.
No prepayment penalty applies on the existing loan.

Sources

Common questions

What is the difference between recasting and paying extra?: Both put the same lump against principal. A recast then re-amortizes the smaller balance over the same remaining term, so your payment falls and the payoff date stays put. Paying extra keeps your payment where it is, so the date moves earlier instead. Recasting costs a few hundred dollars; paying extra costs nothing.
Is recasting or paying extra cheaper?: Paying extra, always, at every rate and every balance. The two start identically and diverge immediately, because a recast reduces every subsequent payment while an extra payment leaves them all working against the balance. The calculator shows exactly what the recast costs, which is the price you pay for the lower monthly payment.
When should I recast instead?: When cash flow is the problem. A recast permanently lowers a fixed monthly obligation for a few hundred dollars, without the credit check, appraisal and thousands in closing costs a refinance needs. If your income has fallen or become less certain, that is worth more than the interest it costs.
Is refinancing better than recasting?: Only if the rate improvement is large enough to clear the closing costs. Refinancing is the only one of the three that changes your rate, so with a big enough drop it wins comfortably; with a small one the fees sink it. The refinance calculator works the breakeven out in detail, including how long you need to stay.
Can any mortgage be recast?: No. FHA, VA and USDA loans generally cannot be recast, and most conventional servicers require a minimum lump sum, a seasoned loan and a fee of $150 to $500. It is also entirely at the servicer’s discretion. Ask before planning around it, the option is less widely available than the arithmetic suggests.
Should the lump go at the mortgage at all?: A separate and often more important question. Paying a mortgage down earns a guaranteed return equal to its rate, which an investment has to beat after tax, mortgage payoff versus investing solves for that bar. If you hold higher-rate debt, clearing that first almost always wins.

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