Should I Refinance? Judge the New Loan, Not Just the New Payment

A refinance is a new loan, not a tweak. It doesn't feel like a big decision: rates tick down, a lender emails you a lower payment, and it looks like you're just adjusting the loan you already have. But the new loan pays off and replaces the old one entirely. That brings:

• a fresh application and qualification under whichever underwriting rules apply to you (see Conventional vs. DSCR Underwriting)
• new property valuation and appraisal requirements, as applicable
• new pricing and loan-level adjustments
• real closing costs
• a new amortization schedule, the part people miss most, which may reset or extend your payoff timeline depending on the term you choose

Once you see it as a replacement, the right question stops being "is the new payment lower?" and becomes "does replacing this loan, all-in, actually serve my objective?"

The trap is that almost everything about a refinance shows up as one number: the payment. And the payment bundles together things that are completely different. Pull them apart. A lower payment can come from:

• a genuinely lower interest rate, which is real savings
• re-stretching the balance over a fresh 30 years, which defers principal and is not savings
• changing the structure to interest-only or a longer term, which lowers the payment with less or no paydown

Those look identical on the statement, but they are not identical at all. It is the same lesson as in the loan-structure guide, applied to the refinance decision: a lower payment is not automatically cheaper debt.

Watch it happen on the canonical deal. Say you're about five years in. The balance is down to about $195,414, with roughly twenty-five years left on the original 6% loan and a payment of $1,259 a month. Suppose rates have fallen and you can refinance at 5% (an illustration — the canonical deal itself stays at 6%). Here's what "the payment dropped" actually contains:

• Refinance the balance at 5% on a fresh 30-year schedule and the payment falls to about $1,049 — a $210-a-month drop. That's the number the offer will lead with.
• But refinance the same balance at 5% over the remaining 25 years — apples to apples, no clock reset — and the payment is about $1,142. So only about $117 a month of that drop is the actual rate savings.
• The other ~$93 a month comes from spreading a smaller balance back over a fresh thirty years, not from the rate. It is payment relief created by slower principal repayment. That leaves you with a higher balance at any future date than the same-rate 25-year refinance would, and more interest than keeping the shorter amortization. (It does not automatically mean more lifetime interest than the old loan. Here the lower 5% rate roughly offsets the longer term, so the fresh-30 and the remaining 6%/25-year loan carry about the same remaining nominal interest. The extra interest is relative to a same-rate 25-year refinance, not the old loan.)

Now add the cost of getting the new loan. Be careful about what "break-even" means here, because there are two different break-evens and they answer different questions. A refinance isn't free. Closing costs typically run a few percent of the loan, plus any points (upfront fees paid to the lender, often to lower the rate). If your existing loan is a business-purpose DSCR loan (one qualified mainly on whether the property's rent covers its payment, rather than on your personal income) with a prepayment penalty, add the cost of paying that loan off early. Say closing costs here are about $3,900.

• Cash-flow payback = the upfront cost divided by your actual monthly payment reduction. If you take the fresh-30 refinance, that's a real $210 less a month, so ≈ $3,900 ÷ $210 ≈ 19 months to recoup the cash you laid out. That's a legitimate number — it tells you when the payment relief has paid back the closing costs.
• Economic break-even is the harder, truer question: are you actually ahead? To answer it, compare the two loans at your expected exit date. For each loan, look at cumulative payments plus the remaining balance (your equity), including the upfront costs, points and any prepayment penalty. This matters because ~$93 of that $210 came from paying principal slower. So at any future date you owe more on the new loan than you would have, and the cash-flow payback alone doesn't capture that. A same-remaining-term comparison is what isolates the roughly $117 a month that comes from the lower rate itself. Hold amortization length constant and that's the part that's genuinely cheaper debt.

In practice, the 19-month cash-flow payback tells you when you've recouped your out-of-pocket cost. Whether the refinance leaves you economically ahead depends on how long you'll hold it and what the reset does to your balance by then. If you'll hold well past the point where the rate benefit outweighs the costs and the slower paydown, it can genuinely pay. If you might sell or refinance again soon, it may not.

"No-closing-cost" refinances don't escape this; they just move the cost. Generally, you don't pay the costs upfront. Instead, the lender offsets them with a lender credit tied to pricing (usually a higher rate), or eligible costs are financed into the new balance. You still pay; it shows up in the rate or the principal instead of at the closing table. Don't mistake it for free.

A refinance can also be about more than rate. Legitimate reasons to replace a loan include:

• escaping a structure you no longer want, such as refinancing out of a balloon or an ARM (adjustable-rate mortgage) before it resets into unknown rates, or out of an interest-only period before it re-amortizes (starts requiring principal payments)
• pulling equity out in a cash-out refinance to redeploy into the next deal

But keep cash-out separate. Those proceeds are debt, not profit. A cash-out refinance is a bigger loan that raises your debt service and changes your capital stack (the mix of debt and equity funding the property). Here, the proceeds count as one input in the decision; the mechanics are in Cash-Out Refinance & the BRRRR Mechanic.

Two boundaries apply. First, a refinance is re-underwritten. You re-qualify under whatever rules apply now, and the new loan is re-priced with current adjustments and reserves. Investment rate-and-term refinances (ones that change the rate or term and take little or no cash out) are also LTV-capped. LTV, or loan-to-value, is the loan as a share of the property's value, and the new loan's LTV can be no higher than a set limit. That limit is currently up to 75% on a one-unit investment property, with lower limits on two-to-four units. So the equity you have determines what's even available. Second, the deepest consequence is what restarting amortization or moving to interest-only does to your principal paydown, your equity, and your total return. This page deliberately doesn't score that long-run wealth effect; Return on Equity & the Wealth Engines explains how principal paydown builds equity as one of a rental's wealth engines. The question here is whether replacing the loan pays for itself and fits your plan.

So judge a refinance as a new loan, not by the new payment. First, split the payment change into real rate savings, re-stretched amortization and structure change. Next, total every cost of replacing the loan: closing, points and any prepayment penalty. Then calculate the cash-flow payback. Finally, test whether the refinance is economically ahead at the date you expect to be out. Keep the cash-out and total-return questions separate. A refinance is a new loan, not a tweak — so decide it like one.