ATTOM's Q1 2026 Housing Risk Rankings Are Out. Florida and California Dominate — and Some 2021 Darlings Made the List.

If You're Still Running Deals Without This County-Level Risk Data, You're Flying Blind

Every quarter, ATTOM releases their Special Housing Risk Report — a county-by-county ranking that layers foreclosure filings, underwater mortgage rates, housing affordability ratios, and local unemployment into a single composite risk score. Q1 2026's report just dropped, and the data tells a story that's both alarming and actionable.

The headline finding: Florida and California counties dominate the highest-risk tier across all four dimensions. But buried in the county-level detail are three things every real estate investor needs to know right now — which markets are early in their stress cycle (buy signal), which are terminal (avoid), and which are being misread by investors still running 2021 analysis frameworks.

The national backdrop sets the stakes: 3.2% of U.S. homes are seriously underwater — meaning the outstanding loan balance exceeds current market value by 25% or more. One in every 1,211 homes carries an active foreclosure filing. And $162 billion in multifamily bridge loans from the 2020-2022 cycle are maturing this year, with heavy concentration in the same counties topping ATTOM's risk list. This is not panic material. It's a map.

The Four-Factor Framework ATTOM Uses — and Why It's Better Than Any Single Metric

Most investors screen deals on cap rate or gross yield. ATTOM's composite risk score forces you to evaluate market health across four dimensions simultaneously — and the combination is what reveals real danger:

1. Foreclosure rate. Active foreclosure filings per housing unit. High foreclosure concentration creates motivated sellers, but it also signals falling comps and competing distressed inventory that can undermine your exit multiple months after you've closed.

2. Seriously underwater mortgages. Properties where the outstanding loan exceeds market value by 25% or more. High underwater concentrations in a county mean a large share of owners can't sell without taking a loss — which either locks them in place and suppresses supply, or creates short sale and distressed deal flow as financial pressure mounts over time.

3. Affordability ratio. The percentage of median local household income consumed by annualized housing ownership costs. When this exceeds 80%, demand destruction sets in hard — fewer qualified buyers means longer days on market and more price concessions when you're trying to exit.

4. Local unemployment. A leading indicator of foreclosure acceleration. Counties where unemployment is already elevated and trending higher are where you'll see the most motivated sellers — and the highest risk of sustained price compression.

No single metric tells the full story. A county with elevated foreclosure filings but strong employment and a 45% affordability ratio may be cycling through a temporary stress event. A county that looks clean on a cap rate screen but carries 17% seriously underwater mortgages and rising unemployment is a trap waiting to spring.

What the Q1 2026 Data Actually Shows

Here's where ATTOM's latest report gets county-specific — and where investors need to update their models:

Kings County (Brooklyn), NY leads the national unaffordability ranking at 108.6% — meaning annualized housing ownership costs consume more than the entire median local wage. That's not a rounding error. It's a structural demand ceiling that makes exit risk real for any investor holding or buying in the borough at current prices.

Ouachita Parish, Louisiana tops the seriously underwater list at 17.4% — nearly 1 in 6 homes in the county has a mortgage balance 25% above current market value. That's a number more associated with 2011 post-crisis conditions than a 2026 housing landscape.

Florida dominates most of the top spots across all four factors. Gulf Coast counties — the same markets that posted 30-40% price appreciation in 2020-2022 — are now showing the convergence of high insurance costs, elevated foreclosure filings, and affordability ratios that have pushed above 60-70% in markets like Cape Coral and Fort Myers. The insurance crisis (average Florida coastal premiums now running $9,000–$18,000 annually for landlord policies) doesn't appear in ATTOM's raw risk score, but it's the accelerant that turns a stressed market into a distressed one.

California coastal counties, particularly in the Central Valley and Inland Empire, appear in the high-risk tier on affordability grounds. Los Angeles and San Bernardino counties carry both extreme affordability ratios and meaningfully elevated unemployment relative to the state average — a combination that limits the buyer pool for your eventual exit.

The national foreclosure rate of 1 in 1,211 homes sounds manageable — and it is, compared to the 1-in-64 rate at the 2010 crisis peak. But a 26% year-over-year increase in filings combined with the $162 billion bridge loan maturity wall hitting this summer suggests the rate is trending, not static. Counties where multiple ATTOM risk factors are deteriorating simultaneously are the ones to watch most closely heading into Q2-Q3.

Common Mistakes Investors Make When Reading This Data

• Treating "risky market" as synonymous with "bad opportunity." The riskiest counties by ATTOM's measure are often where the most motivated-seller inventory lives. The question isn't whether to engage — it's how to price exit risk into your analysis before you make an offer.
• Ignoring the insurance overlay in Florida and Gulf Coast markets. Deals that pencil before insurance underwriting frequently fall apart when landlord premiums come in at $12,000–$18,000 per year on coastal properties. Run the insurance number before you run anything else in any Florida market flagged on ATTOM's list.
• Using trailing comp data that's too long. In markets where 40%+ of listings have cut price in the last 90 days, comps from 12-18 months ago are fiction. Compress your comp window to 60-90 days maximum in any ATTOM high-risk county.
• Missing that the report is a lagging indicator. ATTOM's Q1 score captures stress that has already materialized in filings and valuations. If unemployment is rising and affordability is deteriorating in a county, Q2-Q3 2026 risk levels will be higher than the Q1 report shows. Build a 15-20% downside buffer on exit price assumptions in any market where multiple risk factors are trending the wrong way.

How to Use PropGPT for This

The ATTOM risk data is most powerful when you combine it with deal-level underwriting. Here's how to wire that into PropGPT:

"Pull the Q1 2026 ATTOM risk indicators for [County Name, State] — foreclosure rate, seriously underwater share, affordability ratio, and unemployment rate. Compare each to the national average and flag which direction each metric has moved over the last two quarters."

This gives you a trend-adjusted risk snapshot rather than a static ranking. A county that's improving across all four factors is a very different investment environment than one that's deteriorating even from an elevated starting point.

"I'm underwriting a duplex in [City, County] at $[Purchase Price] with projected rents of $[Rent]. The county appears on ATTOM's Q1 2026 high-risk list. Run a stressed exit scenario: if market prices fall 12% before I sell and insurance comes in at $[X] annually, does this deal still clear a 6.5% cash-on-cash threshold? Show the breakeven price."

Forces the model to build a proper downside case rather than a base-case-only underwriting, which is how most investors get burned in risk-flagged counties.

"Search for properties in [County] with owner equity below 15%, owned for 4+ years, and 60+ days behind on property taxes. Summarize the count, zip code distribution, and average debt load — I'm building a motivated-seller outreach list targeting the stress ATTOM flagged in Q1 2026."

Turns the ATTOM risk signal into a specific prospecting target list before that stress fully hits the MLS.

"Generate a county-level risk comparison table for these five markets I'm evaluating: [Market A, B, C, D, E]. Use the most recent ATTOM data. Rank them on each of the four risk dimensions, then flag which markets have two or more risk factors moving in the wrong direction simultaneously."

Useful for portfolio screening when you're deciding where to deploy capital across multiple geographies.

"I'm targeting distressed multifamily in [County] based on the ATTOM Q1 2026 risk data. What are the three due diligence questions specific to this county's risk profile — insurance environment, local employment base, and bridge loan maturity exposure — that I need answered before I submit an offer?"

Generates deal-specific due diligence protocols tied to county risk factors, not a generic checklist that ignores what's actually driving stress in your target market.

The Bottom Line

ATTOM's Q1 2026 risk data isn't a warning to avoid the most stressed markets — it's a tool for pricing risk correctly before you deploy capital. Florida and California counties that were the hottest markets in 2021 are now showing compound stress: affordability collapse, insurance crisis, and bridge loan maturations landing simultaneously. That convergence creates motivated sellers and below-market entry points, but only for investors who've done the county-level homework before making an offer.

Run ATTOM's four-factor framework on every market you're considering. Pressure-test your exit assumptions in any high-risk county with a 10-15% downside price scenario. And use PropGPT to build the deal-specific stress models that most buyers in these markets are skipping — that's where your edge lives right now.