ARM vs. Fixed Rate Mortgage in Texas: What Every Dallas Buyer Needs to Know in 2026

Should a Dallas buyer choose an ARM or a fixed rate mortgage in 2026?

As of August 2026, the spread between ARM rates and 30-year fixed rates in DFW has narrowed to just 30–40 basis points — down from 75–125 basis points earlier this year. On a $480,000 loan, that difference translates to roughly $76–$115 per month in initial savings. For most Dallas buyers, the 30-year fixed rate is the simpler, safer call. The buyers who still have a clear case for an ARM are corporate relocators with a defined DFW timeline, luxury and jumbo buyers above the $832,750 conforming limit, and buyers taking builder lender ARM incentives on new construction in Frisco, Celina, and Prosper.

By Paul Blair | August 16, 2026

A question coming up constantly from buyers across DFW right now: should I go ARM or fixed?

Six months ago, the answer was more interesting. ARMs were running 0.75 to 1.25 percentage points below the 30-year fixed, and the math was genuinely compelling for the right buyer. In August 2026, that gap has compressed. The 5/6 ARM is averaging around 6.25%, against a 30-year fixed at 6.54%. That's a 29-basis-point difference.

That narrow spread changes the calculus for most buyers. It doesn't make the question irrelevant — it makes it more buyer-specific than it's been all year.

How ARMs Work in Texas

An adjustable-rate mortgage has a fixed rate for an initial period — 5, 7, or 10 years — then adjusts periodically based on a benchmark index plus a lender margin.

Today's ARMs use SOFR (the Secured Overnight Financing Rate) as the index. Your lender adds a margin — typically 2.50 to 3.00 percentage points — on top of whatever SOFR is at each adjustment date.

The two most common structures in DFW right now:

• 5/6 ARM: Fixed for 5 years, adjusts every 6 months after that
• 7/6 ARM: Fixed for 7 years, adjusts every 6 months after that

Both typically carry 2/2/5 caps: maximum 2% increase at the first adjustment, 2% at each subsequent adjustment, and 5% total over the life of the loan. On a 5/6 ARM starting at 6.25%, the worst-case rate ceiling is 11.25%. That's the number worth stress-testing before you sign.

There's no prepayment penalty on conventional conforming ARMs. You can refinance at any point during the fixed period — which matters for buyers who believe rates will drop before their first adjustment date.

What Every Dallas Buyer Needs to Think Through

The rate picture right now

Rates as of mid-August 2026. Rates change daily — confirm with your lender before deciding.

On a $600,000 home with 20% down — typical in Plano, Frisco, and Richardson — the 5/6 ARM saves $76 per month for the first five years. That's $4,560 in cumulative savings over the fixed period.

For a buyer putting 20% down on a $1.1 million home in Highland Park or Preston Hollow ($880K loan), the spread matters more in absolute dollars: a 5/6 ARM at 6.25% versus the 30-year fixed at 6.54% saves $140 per month — over $8,400 across the fixed period. For jumbo buyers, the dollar savings on a larger balance often justify the ARM structure more clearly than the percentage spread alone suggests.

What DFW adds to the equation

Texas property taxes complicate the ARM vs. fixed analysis in a way buyers from other states don't always anticipate.

DFW property tax rates run from 1.71% to 2.50% depending on the city, ISD, MUD, and PID assessments. On a $600,000 home, that's $10,260 to $15,000 per year — $855 to $1,250 per month on top of your P&I. For many buyers, taxes represent 25–35% of total monthly PITI.

Any P&I reduction from an ARM adds real relief to an already-elevated payment. But the rate risk gets amplified on the back end: a 2% rate increase on a $480K loan adds $587 per month to P&I, and your property taxes aren't going down.

The DFW median seller tenure is 7.7 years. A 5-year ARM expires right around when the average DFW homeowner starts thinking about a move. A 7-year ARM might actually outlast your likely tenure — which is either reassuring or irrelevant depending on your situation.

DFW buyer scenario comparison

Who has a real case for an ARM right now

Even with the spread compressed, three buyer profiles in DFW still have a strong argument:

Corporate relocators. DFW continues to attract major employers — Toyota in Plano, Goldman Sachs expanding its Dallas footprint, McKinney capturing executive moves from the Northeast. If you're a corporate relocator with a defined 5- to 7-year DFW assignment, a 7/6 ARM aligns your rate risk with your anticipated timeline. You get a lower rate through the likely duration of your stay, then either sell or refinance before the first adjustment.

Luxury and jumbo buyers. Above the conforming loan limit of $832,750, you're in jumbo territory — Highland Park, University Park, parts of Preston Hollow, and larger estates in Southlake and Westlake. Jumbo ARM rates can run more favorable than jumbo fixed rates, and the absolute dollar savings on a larger balance are real. What DFW luxury buyers need to know about jumbo loan qualifying standards walks through reserve requirements, credit benchmarks, and lender expectations at that tier.

New construction buyers with builder ARM packages. Builders across the northern corridor — Frisco, Celina, Prosper, and Anna — are offering ARM buydown packages through their preferred lenders that can deliver initial rates well below market. These are worth evaluating, but compare the total package against an independent lender offer. Some builder incentives inflate the purchase price to fund the rate buydown.

If you want to run the full payment picture on a specific DFW property — including property taxes, HOA, and total PITI under both loan scenarios — I'm happy to walk through it. Connect here.

Who should stick with a 30-year fixed

The fixed rate makes more sense if:

• You're planning to stay 10+ years (rate risk compounds past the ARM ceiling math)
• You're a first-time buyer already at your price ceiling (the certainty of a fixed payment is worth more than $76/month)
• You're buying in the $450K–$650K range in McKinney, Wylie, Murphy, or Sachse with an open-ended timeline
• You're already carrying elevated property taxes and want payment predictability

There's an alternative worth considering instead of an ARM: use seller concessions to buy down your fixed rate. In today's DFW buyer's market, negotiating a 1-2 point seller-paid buydown can reduce your fixed rate meaningfully without adding adjustment risk. Here's how mortgage points work in Texas and when a buydown beats the ARM math.

The refinance option before adjustment

If you take an ARM and rates fall materially before the first adjustment, you can refinance to a fixed rate without penalty. The practical question is break-even on refinancing costs.

If you refinance from a 6.25% ARM to a 5.75% fixed rate, you're saving roughly $140 per month on a $480K loan. Closing costs on a refinance typically run 2–3% of the loan amount — $9,600 to $14,400 on that balance. At $140/month saved, break-even is roughly 68 to 103 months. That's often longer than buyers expect when they're counting on a quick refinance to protect their ARM strategy.

Frequently Asked Questions

What's the difference between a 5/1 ARM and a 5/6 ARM?

Both have a 5-year fixed period. The difference is adjustment frequency after that: a 5/1 ARM adjusted annually, while a 5/6 ARM adjusts every 6 months. The 5/6 structure is now standard for conforming loans under the SOFR index. More frequent adjustments mean faster potential rate increases, but also faster rate reductions if SOFR falls.

Are ARM rates always lower than fixed rates in Texas?

Not always. In August 2026, the ARM-to-fixed spread is just 30–40 basis points — historically narrow. The spread was 75–125 basis points in early 2026 and has since compressed. Spreads widen when the market expects rates to fall over the medium term, and narrow when the yield curve prices in flat or rising rates.

Can I lock an ARM rate before closing in DFW?

Yes. ARM rates can be locked for 30, 45, 60, or 90 days, just like fixed rates. Extended lock periods carry a fee, which matters most for new construction buyers with longer build timelines. Your lender will walk you through the rate lock options for the specific ARM product you're considering.

Do Texas property taxes affect which mortgage type I should choose?

Not directly, but the full PITI picture matters. With property taxes adding $855 to $1,250 per month on a $600K DFW home, total payments are already elevated. Some buyers find the certainty of a fixed P&I payment more valuable in that context; others use the ARM's initial savings to offset the tax burden. It depends on your cash flow priorities and how long you plan to stay.

How do I find an agent in DFW who can help me think through the ARM vs. fixed decision before I start shopping?

This conversation is most useful before you finalize your search criteria, because the loan structure affects your purchase price ceiling and monthly payment planning. Work with an agent who asks about your timeline, your likely tenure in DFW, and your employment situation — a strong buyer's agent will surface the right mortgage conversation early, connect you with multiple lenders, and help you stress-test worst-case payment scenarios before you're under contract.

The right loan structure depends on your DFW timeline, property type, and total payment picture. If you want to walk through the numbers for a specific property or buyer scenario, reach out here.

The ARM vs. fixed decision in 2026 doesn't have one right answer — it has one right answer for your situation. With the spread at 30–40 basis points right now, the era of easy ARM arbitrage in DFW has narrowed. But for buyers with a clear timeline, a jumbo loan, or a builder incentive worth evaluating, the analysis is still worth running.

I've helped corporate relocators buying in Plano and Frisco run this exact calculation — when you're coming in with a defined timeline, the mortgage structure matters as much as the price.

About Paul Blair

Paul Blair is the founder and broker of Grey Square, a virtual real estate brokerage representing buyers and sellers across Dallas and Los Angeles. With 22 years in the business and more than $200 million in closed transactions, Paul works the full range of the market, from luxury homes in the Park Cities and Preston Hollow to estates in the Hollywood Hills and across the Westside. Connect with Paul and the Grey Square team at greysq.com. TX TREC #9011505 · CA DRE #01792671.