If you've come into a lump sum of cash and want to lower your mortgage payment, you have two main options: a mortgage recast or a refinance. A recast keeps your current loan and interest rate but lowers your monthly payment by applying a lump sum to your principal, while a refinance replaces your loan entirely with new terms. For most homeowners with a low interest rate, a recast saves more in upfront costs, but a refinance can save more over time if current rates are significantly lower than your existing rate.
Choosing wrong can cost you tens of thousands of dollars over the life of your loan. Let's break down exactly how each option works, run the numbers side by side, and help you figure out which path makes the most financial sense for your situation.
What Is a Mortgage Recast vs. Refinance and How Does It Work?
A mortgage recast (also called a re-amortization) is when your lender recalculates your monthly payment based on a lower remaining principal balance after you make a large lump-sum payment. Your interest rate, loan term, and lender all stay exactly the same. The only thing that changes is your monthly payment, which drops because the loan is now amortized over the remaining term using a smaller balance.
A refinance, by contrast, pays off your existing mortgage with a brand new loan. You get a new interest rate, potentially a new loan term (typically 15 or 30 years), and you start the amortization clock over. You'll go through underwriting, an appraisal, and pay closing costs that typically run 2% to 5% of the loan amount.
Concrete example: Say you have a $320,000 mortgage at 6.5% with 28 years remaining and a $2,023 monthly payment. You inherit $50,000 and want to put it toward your mortgage.
- Recast option: You pay $50,000 toward principal. Your lender charges a $300 recast fee and re-amortizes the remaining $270,000 over 28 years at 6.5%. New payment: roughly $1,707/month — a savings of $316/month.
- Refinance option: If you can refinance the remaining $270,000 at 5.5% over 30 years, your payment drops to about $1,533/month. But closing costs of $8,100 (3%) come off the top, so you actually have less cash left over.
The plain-English math formula for a recast is: (Current balance − lump sum) re-amortized over remaining term at current rate = new monthly payment. For a refinance, it's: (Current balance − lump sum, if any) amortized over new term at new rate + closing costs = new monthly payment and total cost.
How Much Can You Actually Save?
The savings depend heavily on three variables: your current rate, available market rates, and how much cash you're putting down. Below is a comparison using a $320,000 mortgage at 6.5% with 30 years remaining, showing standard payments versus three scenarios where you add monthly extra payments OR a lump sum recast.
| Scenario | Monthly Payment | Total Interest | Payoff Date | You Save |
|---|---|---|---|---|
| Standard 30-yr at 6.5% | $2,023 | $408,142 | 30 years | — |
| Add $100/month extra | $2,123 | $340,168 | 26 yr 4 mo | $67,974 |
| Add $250/month extra | $2,273 | $268,290 | 22 yr 2 mo | $139,852 |
| Add $500/month extra | $2,523 | $197,420 | 17 yr 9 mo | $210,722 |
| $50K Recast (no extra) | $1,707 | $303,512 | 30 years | $104,630 |
| Refinance to 5.5%, 30-yr | $1,817 | $334,118 | 30 years | $74,024 (minus $9,600 closing) |
As you can see, simply adding extra to your monthly payment can outperform both options if you're consistent. Use our extra payment calculator to model your exact numbers. A recast wins when you have a low rate already and just want to reduce your monthly cash outflow. A refinance wins when market rates drop at least 0.75–1% below your current rate and you plan to stay in the home long enough to recoup closing costs.
Step-by-Step: How to Decide Between a Recast and Refinance
- Check your current interest rate against today's market. Pull up your mortgage statement and look up current 30-year and 15-year rates. If today's rates are 1% or more below yours, refinancing deserves serious consideration. If rates are higher or similar, recasting is almost always the better play.
- Call your lender to confirm recast eligibility. Not all loans qualify — FHA, VA, and USDA loans typically cannot be recast, and most lenders require a minimum lump sum of $5,000 to $10,000. Ask about the recast fee (usually $150 to $500) and any seasoning requirements.
- Get refinance quotes from at least three lenders. Request a Loan Estimate from each, which itemizes closing costs, the new rate, and the APR. Compare these side by side — don't just look at the rate, because lender fees can vary by thousands.
- Calculate your break-even point on a refinance. Divide total closing costs by your monthly savings. If closing costs are $8,000 and you'd save $200/month, your break-even is 40 months. If you plan to move before then, refinancing loses money.
- Run both scenarios through an amortization tool. Use a detailed amortization schedule calculator to compare total interest paid under each option. This is where the real long-term winner reveals itself.
- Consider hybrid strategies. Sometimes the smartest move is a recast PLUS biweekly payments, or putting half your lump sum toward principal and investing the rest. Explore payoff strategies that combine methods.
- Submit your paperwork and verify the change. For a recast, send the lump sum payment plus a written recast request. For a refinance, you'll go through full underwriting. In both cases, get the new amortization schedule in writing before celebrating.
Common Mistakes Homeowners Make with Recast vs. Refinance Decisions
- Refinancing just to lower the monthly payment without doing the math. Extending a 22-year remaining loan back out to 30 years lowers your payment but can add tens of thousands in interest. Always compare total interest paid, not just monthly payments.
- Ignoring closing costs in the refinance equation. A "no-cost" refinance usually means the costs are rolled into a higher rate or loan balance. There's no such thing as truly free money — read the Loan Estimate carefully.
- Assuming all lenders allow recasts. Many homeowners send a big payment expecting their payment to drop, only to discover the lump sum was just applied to principal without re-amortization. You must specifically request a recast in writing and confirm eligibility first.
- Forgetting that extra monthly payments can beat both options. Consistently paying an extra $200-$500 per month often saves more than either a recast or refinance, while keeping your full liquidity in case of emergency. Consider a biweekly payment plan as a simple alternative.
Is a Recast or Refinance Right for You? Key Questions to Ask
1. Is your current interest rate already low (under 5%)? If yes, a recast is almost certainly better — refinancing into a higher rate makes no sense even if your monthly drops temporarily. Keep your golden-handcuff rate and just reduce the balance.
2. Do you have a large lump sum (at least $10,000) available? A recast requires meaningful principal reduction to move the needle. If you only have $3,000-$5,000, you're better off just making it an extra principal payment without paying a recast fee.
3. Will you stay in the home for at least 5 more years? Refinancing only pays off if you stay long enough to recover closing costs. If you might sell or relocate within 3-4 years, a recast — or no action at all — usually wins.
4. Is your goal lower payments or faster payoff? Recasting and refinancing both lower payments but extend your debt timeline. If your real goal is becoming mortgage-free, throwing extra at principal each month (without recasting) is the most powerful approach.
Frequently Asked Questions
How much does a mortgage recast typically cost?
Most lenders charge between $150 and $500 for a recast. Compare that to refinance closing costs of 2-5% of the loan balance — on a $300,000 loan, that's $6,000 to $15,000. The recast fee is one of the biggest advantages of this strategy.
Can I recast my FHA or VA loan?
No. FHA, VA, and USDA loans cannot be recast under their program rules. If you have one of these government-backed loans, your only options are making extra principal payments or refinancing into a new loan (potentially a conventional one).
Does a recast change my interest rate?
No. Your interest rate, loan term, and lender stay identical after a recast. Only your monthly payment changes because it's recalculated based on the lower remaining principal balance amortized over the remaining term.
How long does a refinance take compared to a recast?
A refinance typically takes 30-45 days from application to closing, with full underwriting, appraisal, and document review. A recast usually processes in 5-10 business days because no underwriting is required — your lender just recalculates and sends you a new amortization schedule.
Will a recast hurt my credit score?
No. A recast doesn't involve a credit pull or new loan, so it has zero impact on your credit. A refinance, however, triggers a hard credit inquiry and shows as a new account, which can temporarily ding your score by 5-15 points.
The bottom line: if you have a low interest rate and a chunk of cash, recasting almost always wins on cost, speed, and simplicity. If current rates are significantly below your existing rate AND you plan to stay in the home for years, refinancing can deliver larger long-term savings — but only after you've crunched the break-even math. Before making any move, run the numbers yourself with our extra payment and recast calculator to see the exact dollar impact for your specific loan.