Earthquake Risk and Insurance When Buying a House in Snohomish or King County (2026)

Short answer: A standard homeowners policy doesn’t cover earthquake damage, and the Puget Sound region has real earthquake risk. If you’re buying in Snohomish or King County, check two things during your inspection period. First, the ground: look up liquefaction and soil maps on the state’s Geologic Information Portal. Second, the house: find out whether it’s bolted to its foundation and whether there are known weak spots. Then get an earthquake quote. Deductibles are a percentage of the coverage amount, often 10% or more.

This is general information, not engineering, legal or insurance advice. For a specific house, talk to a licensed engineer or contractor about the structure and to an agent or broker about coverage.

The risk in the Puget Sound region

The Washington Geological Survey (part of DNR) cites the first U.S. Geological Survey earthquake forecasts for western Washington:

Data from: Washington Geological Survey (DNR), Earthquakes and Faults page and A Homeowner’s Guide to Earthquakes in Washington State.

The Southern Whidbey Island fault zone matters to Snohomish County buyers in particular. DNR says it likely connects with the Rattlesnake Mountain fault zone near Maltby. Washington Emergency Management says more than 1,000 earthquakes happen in the state each year, and a dozen or more are strong enough to feel.

Check the ground under the house

DNR says the soil under a house affects how hard it shakes. Soft materials and loose soils, common near water and in formerly glaciated areas like the Puget Sound region, amplify shaking. Hard rock shakes less. Its homeowner guide names artificial fill, beach sand, dunes, river deposits and young sediment as especially prone to liquefaction, where water-saturated sediment behaves like a liquid.

After the 2001 Nisqually earthquake, DNR made two kinds of maps for every county in the state: liquefaction susceptibility maps and NEHRP site class maps, which show where soils amplify shaking. Both are on the free Geologic Information Portal. Look up the address before you remove your inspection contingencies. A high-hazard area doesn’t rule a house out, but it’s a reason to look harder at the foundation and the insurance.

Houses on slopes or bluffs face earthquake-triggered landslides, DNR says, especially when soils are saturated. If the lot is on or near a slope, see our guide to buying a house on a slope. Low-lying waterfront property may also need a flood check; see buying a home in a flood zone.

Check the house

DNR’s homeowner guide says the building code used when a house was built may not reflect what’s known now about earthquake hazards. Its timeline of code changes is a useful way to read a listing’s year built:

• 1955: earthquake standards for construction included in Washington law.
• 1975: first building code adopted by Washington State.
• 1997: Uniform Building Code published with seismic changes.
• 2000: International Building Code published.
• 2005: Seattle fault and Cascadia subduction zone first included in the Washington Building Code.

Based on: Washington Geological Survey, A Homeowner’s Guide to Earthquakes in Washington State, Timeline of Seismic Building Code Updates.

Year built is only a starting point. Remodels and retrofits change the picture. Ask your inspector to note these items from DNR’s guide:

• Bolting. On a stem-wall foundation, the wood frame has to be bolted or anchored to the concrete. DNR says many older houses aren’t.
• Cripple walls. Short wood walls in a crawlspace between the foundation and the first floor can buckle without plywood or OSB shear panels.
• Post and pier. DNR calls this foundation type extremely vulnerable if not properly braced and recommends an engineer.
• Soft stories. A garage or large openings under living space can be a weak point.
• Masonry. Unreinforced brick or block foundations and chimneys often fail. Washington Emergency Management says unreinforced masonry buildings were typically built before 1958.
• Water heater. It should be strapped at the top and bottom with heavy-gauge metal straps.

A general home inspection may note some of these but isn’t a seismic evaluation; see what a standard home inspection covers. For a structural question, DNR suggests a licensed engineer or contractor. If a past retrofit or addition was done without permits, see our guide to unpermitted work.

Also read the seller disclosure. Form 17 asks whether there’s material damage to the property from earthquake, among other causes (7C), and whether there’s been any settling, slippage or sliding of the property or its improvements (4E). RCW 64.06.020 currently has two versions on the Legislature’s site: one marked effective until January 1, 2027, and one effective January 1, 2027. The questions quoted here appear in both. If your sale runs across the new year, check which form is being used.

How earthquake insurance works in Washington

The CFPB says standard homeowners insurance doesn’t cover earthquakes, but you may be able to add it. The OIC says you can add earthquake coverage to a homeowners policy or buy it separately. Its homeowner guide says not all companies offer it.

Based on: Washington OIC, Earthquake insurance page. Policies vary; read the one you’re quoted.

Points to understand before you buy a policy:

• The deductible is a percentage. The OIC’s earthquake page says deductibles are usually 10% to 25% of the building limit; its homeowner guide says usually 10 to 20 percent. The policy pays only damage above that amount.
• There can be more than one deductible. Separate deductibles may apply to the house, its contents, and unattached structures like garages, sheds, driveways or retaining walls.
• You can’t wait for the shaking. The OIC says that after an earthquake, you usually have to wait a while before you can buy coverage.
• The insurer may inspect. Some may require bolting the house to its foundation, bracing interior walls, or strapping the water heater.
• Construction matters. The OIC guide says masonry structures are more susceptible to earthquake damage than wood frame.

Fitting it into your purchase

1. Look up the address on the Geologic Information Portal before or right after your offer.
2. Read Form 17 sections 4E and 7C, and ask about any past retrofit or damage.
3. Have your inspector note bolting, cripple walls, chimney and water heater strapping. Bring in an engineer if something looks off.
4. Get homeowners and earthquake quotes during the inspection period, and ask the insurer what it requires.
5. Decide on retrofit work and coverage before your contingency deadline passes.

For questions about an insurer or a policy, the OIC’s Consumer Advocacy line is 800-562-6900. See the closing process for the rest of the timeline.

FAQ

Does homeowners insurance cover earthquakes in Washington?

Usually not. The CFPB says standard homeowners insurance doesn’t cover earthquake damage, though you may be able to add it. The Washington insurance commissioner’s office says you can add earthquake coverage to a homeowners policy or buy it separately, and that not all companies offer it.

How much is the earthquake insurance deductible?

The Washington insurance commissioner’s earthquake page says deductibles are usually 10% to 25% of the building coverage limit; its homeowner guide says usually 10 to 20 percent. Either way, it’s a percentage of the coverage amount, not a flat dollar figure. There may be separate deductibles for the house, its contents and detached structures.

How likely is a big earthquake near Seattle and Everett?

The Washington Geological Survey says that as of 2025, in the Puget Sound region, there’s an 85% chance of at least a magnitude 6.5 deep earthquake in the next 50 years. It puts the chance of a magnitude 9 Cascadia megathrust quake at 15%, and the chance of at least a magnitude 6.5 shallow crustal quake at 17%, over the same period.

Does earthquake insurance cover landslides and liquefaction damage?

Often not fully. The commissioner’s office lists damage from landslides, settling ground, mudflows, and earth rising, sinking or contracting under what earthquake insurance doesn’t cover. It says the policy may cover costs to stabilize the land under the house. Read the exclusions in any policy you’re quoted.

Should I get an earthquake retrofit before buying?

It’s a purchase decision, not a requirement. The Washington Geological Survey says many older houses aren’t bolted to their foundations and recommends a professional engineer for weak spots like unbraced cripple walls, post-and-pier foundations and soft stories. Some earthquake insurers may require bolting, wall bracing or a strapped water heater before they’ll cover the house.

Talk it through with a local agent

Peter Kim and Odigo Real Estate Club can help you fit the map check, inspection and insurance quotes inside your deadlines, with 25+ years combined experience, 593+ closings, and 122 five-star Zillow reviews. See our home buying services.

Odigo Real Estate Club · REAL Brokerage, WA #112064 · 16108 Ash Way, Suite 201, Lynnwood, WA 98087 · (425) 409-3823 · Mon–Sat 9 AM–6 PM, closed Sunday

Sources

• Washington State Office of the Insurance Commissioner, Earthquake insurance (add-on or separate policy; deductibles usually 10%-25% of the building limit; separate deductibles; waiting period after a quake; covers, may cover, doesn’t cover; insurer inspections and requirements; Consumer Advocacy 800-562-6900), https://www.insurance.wa.gov/earthquake-insurance , accessed Nov 3, 2026.
• Washington State Office of the Insurance Commissioner, A consumer’s guide to: Homeowner insurance (PDF) (earthquake coverage optional and not offered by all companies; separate deductible usually 10 to 20 percent; masonry more susceptible to earthquake damage), https://www.insurance.wa.gov/sites/default/files/2025-03/homeowner-insurance-guide.pdf , accessed Nov 3, 2026.
• Consumer Financial Protection Bureau, What is homeowner’s insurance? Why is homeowner’s insurance required? (standard homeowners insurance doesn’t cover earthquakes or floods), https://www.consumerfinance.gov/ask-cfpb/what-is-homeowners-insurance-why-is-homeowners-insurance-required-en-162/ , accessed Nov 3, 2026.
• Washington Geological Survey (DNR), Earthquakes and Faults (2025 Puget Sound 50-year probabilities (85%, 15%, 17%); Seattle fault and Southern Whidbey Island fault zone up to about M7.5; SWIF near Maltby), https://dnr.wa.gov/washington-geological-survey/geologic-hazards-and-environment/earthquakes-and-faults , accessed Nov 3, 2026.
• Washington Geological Survey (DNR), Geologic Hazard Maps (liquefaction susceptibility and NEHRP site class maps for every county), https://dnr.wa.gov/washington-geological-survey/geologic-hazards-and-environment/geologic-hazard-maps , accessed Nov 3, 2026.
• Washington Geological Survey (DNR), A Homeowner’s Guide to Earthquakes in Washington State (PDF) (building code timeline; soils and liquefaction; foundation types, bolting, cripple walls, soft stories, chimneys, water heaters; Nisqually M6.8; Cascadia 1700), https://dnr.wa.gov/sites/default/files/2025-04/ger_homeowners_guide_earthquakes.pdf , accessed Nov 3, 2026.
• Washington Geological Survey (DNR), Geologic Information Portal (interactive hazard maps), https://geologyportal.dnr.wa.gov/ , accessed Nov 3, 2026.
• Washington Emergency Management Division, Earthquake (more than 1,000 earthquakes a year; unreinforced masonry typically pre-1958), https://mil.wa.gov/earthquake , accessed Nov 3, 2026.
• Washington State Legislature, RCW 64.06.020 (seller disclosure statement form; version effective until Jan 1, 2027 and version effective Jan 1, 2027), https://app.leg.wa.gov/RCW/default.aspx?cite=64.06.020 , accessed Nov 3, 2026.

‍