New homes are offering 4.99% mortgages. Here's when the math works.

You've spent two years watching mortgage rates and telling yourself you'll buy when they come down. Now an ad appears: a new community in the suburbs, granite countertops, and a mortgage rate of 4.99%. The market rate this week is 6.53%. You click. You're suspicious. You're also slightly desperate to know if this is real.

It's real. Sixty percent of new-home builders were offering some form of rate incentive in 2026, according to NAHB and John Burns Research. Lennar and DR Horton — two of the three largest US homebuilders — have been permanently buying mortgage rates down to 4.99–5.5% on select inventory. On a $400,000 loan, 4.99% saves you $391 a month versus 6.53%. That's $4,692 a year, every year, for 30 years.

But before you call the sales office, you need to run one piece of math. Because there is a price at which the lower rate stops saving you money — and the builder almost certainly priced their homes knowing exactly where that line is.

How builders are creating 4.99% mortgages in a 6.53% world

A builder rate buydown works the same way any mortgage rate buydown works — someone pays discount points upfront to permanently reduce the interest rate. One discount point equals 1% of the loan amount ($4,000 on a $400,000 loan) and typically reduces the rate by around 0.125–0.25 percentage points on a 30-year fixed. To bring a rate down from 6.53% to 4.99% — a 1.54-point reduction — costs roughly $16,000–$24,000 in points on a $400,000 loan.

The builder pays that cost as a sales incentive. It comes out of their margin, the same way a car dealer might absorb the cost of low-APR financing to move units. Lennar's average incentive package in early 2026 was 13.3% of sale price — roughly $60,000 on a $450,000 home. That's a lot of room to buy down a rate.

The builders advertising 4.99% permanently in 2026 are using their preferred lending partners — in-house or affiliated lenders who can structure the deal as part of the purchase package. This means you'll typically be required to use their lender to get the rate. That's worth scrutinizing: always compare the full APR, origination fees, and any added closing costs from the preferred lender against an independent broker quote. The rate headline doesn't tell you the total cost of credit.

The $391/month math

Here's the actual monthly payment comparison, using the standard 30-year P&I formula, on a $400,000 loan:

Those are real numbers. $391 a month is a car payment, a grocery run, or one less thing keeping you up at night. Over seven years it exceeds the builder's cost to buy the rate down in the first place — meaning from the builder's perspective, the incentive is effectively self-funding. They give up $20,000 upfront and you give them the sale. That's the trade.

The catch is not the rate. The catch is the price.

The price premium that erases the saving

New construction commands a premium over resale. Historically it runs 10–20% above comparable existing homes, and in 2026 — with supply elevated and builders actively moving inventory — that premium has been compressing in most Sun Belt markets. Even so, if you're comparing a $400,000 resale to a new community, the equivalent new home likely starts at $440,000–$480,000.

Here's the math that every buyer needs to run before they tour a model home:

This rule holds regardless of loan size. The math scales linearly — so whether you're looking at a $300,000 loan or a $600,000 loan, the break-even is always around an 18% price premium versus a comparable resale at today's rates. Run the numbers for your specific situation using the table below:

If the new home you're looking at is priced within 18% of a comparable resale, the builder rate buydown is putting real money in your pocket every single month. If the premium is 22–25%, you're effectively paying a premium in disguise — a lower rate on a much higher loan balance, netting out to a higher payment than the resale.

The math points toward new construction being genuinely cheaper — not just cheaper-feeling — in markets where builders have been cutting prices to clear inventory. Phoenix, Austin, Jacksonville, and Charlotte are all markets where the new-vs-resale premium has compressed to under 10% in 2026. In those markets, the 4.99% deal is hard to beat.

Rate buydown vs. price cut: which is worth more?

Thirty-six percent of builders are also cutting base prices — by around 5% on average in 2026. If the builder is offering either a rate buydown to 4.99% or a 5% price cut, which should you take?

On a $450,000 home:

• A 5% price cut saves $22,500 on the purchase price. At 6.53%, that reduces your loan to $427,500 and cuts your monthly payment by about $120/month.
• A permanent buydown to 4.99% on the full $450,000 loan saves $439/month versus the market rate.

The rate buydown wins by a significant margin if you're staying 3+ years. The price cut only wins if you're putting the difference toward a larger down payment or if you're confident you'll refinance within 18–24 months — in which case the buydown rate disappears anyway (more on that below).

If you can negotiate both — a modest price reduction and a rate incentive — that's the optimal outcome. Builders in soft inventory markets are often willing to stack incentives, particularly on completed homes sitting unsold. The rule: always start by asking for a price cut first, then negotiate the rate buydown as a second concession.

The refinance question

Here's the thing nobody in the sales office will bring up: if rates fall to 5.5% in 18 months, you'll want to refinance. And the moment you do, the builder's 4.99% is gone. You return to market rate — whatever that happens to be — and absorb standard closing costs of $6,000–$8,000 to do it.

This changes the math on how you should value the buydown. If you believe rates will fall within two years, the builder's incentive is worth less than it looks — you're paying a price premium for a rate you'll only have briefly. If you believe rates stay elevated for three-plus years, the buydown is worth exactly what the table shows.

The Federal Reserve's "higher for longer" stance through early 2026, combined with ongoing geopolitical inflation pressure, makes a sub-6% market rate before late 2026 unlikely based on current forecasts. Three years of $391/month savings is $14,076 in your pocket before you even think about refinancing.

When new construction wins — and when it doesn't

The math favors new construction when:

• The price premium over comparable resale is under 15% (well inside the 18% break-even)
• The buydown is permanent, confirmed in writing on the loan term sheet
• You're planning to stay at least 3 years — long enough to bank real savings
• The new home is in a market with active builder competition (Sun Belt metros with elevated inventory)

New construction is the wrong call when:

• The price premium exceeds 20% and the builder won't negotiate — you're paying more per month despite the lower rate
• The deal is a temporary 2-1 buydown, not a permanent rate reduction
• You're in a tight supply market where new construction is scarce (the Pacific Northwest, much of the Northeast) — pricing power stays with the seller
• The preferred lender's APR, after fees, is meaningfully higher than what an independent broker would offer you at market rate

Frankly, if you're in a Sun Belt market, have been sitting on the sidelines because of rate anxiety, and can find a new community where the price premium versus resale sits under 15%, the 4.99% deal is the most buyer-friendly environment in six years. Run the numbers on the specific home. If the monthly payment on the new construction is lower than or equal to the monthly payment on a comparable resale at 6.53%, you don't need rates to fall. The math already works.