How Much Does Radon Mitigation Cost in Colorado in 2026?

A standard sub-slab depressurization system in Colorado runs $1,200–$2,500 installed, with $1,500 the most common all-in price for a typical Front Range home with a basement. Crawlspace installs cost more ($2,000–$5,000). About 70% of jobs come in at the standard price; the rest are driven up by harder access, multiple foundation types, or post-install retesting.

That's the straight-up, non-fluff info you probably wanted but was buried or non-existent on most radon company websites. The rest of this post is what changes that number — and why your quote may land on either end of the range depending on your home or which Colorado county you're in.

Quick context: why so many Colorado homes need mitigation

Nearly half of every Colorado home tested in the past two decades has come back over the EPA action level for radon. Across 214,362 pre-mitigation tests submitted to CDPHE between 2005 and 2024, 46.9% read above 4 pCi/L — several times the national rate. Boulder County submitted readings average around 12 pCi/L and Larimer near 7.8, both well above the action level on their own.

"Radon is the leading cause of lung cancer for non-smokers and the second leading cause of lung cancer for the general population." — EPA, Consumer's Guide to Radon Reduction (2025)

In Colorado, mitigation isn't a rare scenario; it's the median home-buying situation.

What the $1,500 actually buys

The $1,500 buys a sub-slab depressurization (SSD) system — what the EPA calls "the most common and usually the most reliable radon reduction method." A radon-rated fan installs in the attic or on an exterior wall, pulling air from a single suction point cut into your basement slab through 3-inch PVC and venting it above the roofline. EPA notes that "often, only a single suction point is needed." Most installs take 4–6 hours.

A reputable Colorado mitigator includes a post-install retest (a 48–96 hour passive test) to confirm levels dropped below 4 pCi/L, plus a written guarantee tying the price to that result. Colorado law requires mitigators to be NRPP-certified or AARST-certified — the EPA-recognized credentials — and to be licensed by the Colorado Department of Public Health and Environment. Don't accept a quote from anyone without both.

The system reduces indoor radon by up to 99% in the majority of homes after a single install — a number EPA itself uses in its consumer guidance. Post-install retest is included with most reputable mitigators in Colorado.

What pushes the price above $1,500

A handful of factors move the quote up:

• Crawlspace mitigation. Vapor-barrier-and-tie-in installs run $2,000–$5,000 depending on crawlspace size and condition.
• Multiple foundation types. A home with a basement plus a crawlspace addition often needs two systems.
• Hard access for the venting run. Long horizontal runs, finished ceilings, or no clean exterior path add labor.
• High starting levels. Homes testing 20+ pCi/L sometimes need a higher-CFM fan or a second suction point.
• Slab depth or sub-slab material. Tight, uniform aggregate is easier to depressurize than poorly compacted fill.

What pulls the price below $1,500

• New construction or recent build. Builders who roughed in passive radon piping during construction make active mitigation a $500–$800 fan-only job.
• Townhomes and patio homes with shared walls, smaller footprints, simpler venting.
• Bundled inspection deals. Some real-estate-driven inspections come with a discounted mitigation quote built into the package.

County-level pricing variation

The price range above holds across most of the Front Range — Tim and Alex's actual service area is south to Castle Rock, east to the Colorado border, north to Fort Collins, and west to Winter Park, covering Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer, Weld, Grand, and the eastern plains counties. Quotes outside that radius (El Paso County / Colorado Springs, Pueblo, Western Slope) often include a drive-time fee from whichever mitigator covers the area.

The CDPHE data shows where the demand is concentrated even when the price doesn't move much:

| County | % of tests over 4 pCi/L | Notes | |---|---|---| | Larimer | 54.9% | Highest of the metro counties | | Boulder | ~50% | Boulder homes average 12 pCi/L per submitted readings — outlier high | | Adams | 46.8% | Right at the statewide median | | Denver | ~44% | Slightly below statewide | | El Paso (Colorado Springs) | ~50% | High demand; outside our direct service area |

Full county-by-county data is in our free Colorado Radon Risk Map.

What "qualified mitigator" actually means

Two credentials are non-negotiable in Colorado: NRPP (National Radon Proficiency Program) or AARST (American Association of Radon Scientists and Technologists) certification, and a current Colorado state license issued by CDPHE. Without both, a "mitigator" is operating outside the law — and any guarantee they issue is unenforceable.

The EPA puts the why bluntly:

"Without the proper equipment or technical knowledge, you could actually increase your radon level or create other potential hazards and additional costs." — EPA, Consumer's Guide to Radon Reduction (2025)

A qualified mitigator also includes:

• Post-install retest, written into the contract. A passive test 48–96 hours after install, results delivered to you. The EPA recommends this be done within 30 days of installation, and notes that "having an independent tester perform the test, or conducting the measurement yourself, will eliminate any potential conflict of interest."
• Written guarantee on the result. Standard guarantee is below 4 pCi/L; some mitigators offer below 2 pCi/L for an upcharge.
• Permit pulled where required. Some Colorado jurisdictions require a mechanical permit for radon-rated fans on the exterior. A mitigator who skips the permit is offloading the liability to you.

If a quote comes in 30%+ below the standard $1,500 and skips any of the three above, that's the warning sign. The savings come from cutting the retest, the guarantee, or the permit — not from a more efficient install.

Skip the shopping — get an honest quote

Comparison-shopping radon mitigation in Colorado is harder than it looks. Online "starting prices" range from around $750 as a marketing entry point up to $3,500 for complex installs, and cheaper quotes often skip the parts that matter — the post-install retest, the permit, the written guarantee. Two quotes at the same dollar amount can mean two different jobs.

A legitimate quote should be free, take 15–30 minutes (in person, or via Zoom plus a few photos), and arrive in writing with:

• System type and fan model
• Full vent path
• Post-install retest commitment
• Written guarantee on the result (below 4 pCi/L standard)
• Permit fees if your jurisdiction requires one

We do that filtering for you. Fill out our free quote form and we'll connect you with an NRPP-certified mitigator we already trust on all five items above — for your specific home, in your specific county. Most homeowners hear back within one business day, and the quote itself is always free.

Frequently asked questions

Does insurance cover radon mitigation?

Generally no. Most insurers classify radon mitigation as a home maintenance issue rather than a covered hazard event. A small number of policies offer rider coverage, and HSA funds may apply in documented health-related cases — check your specific policy, but don't assume.

Is mitigation a one-time cost?

Mostly. The fan is rated for 5–10 years and runs about $25–$40/year in electricity. A replacement fan when it eventually fails is $200–$400 installed. EPA recommends "retest[ing] your home at least every two years to be sure radon levels remain low," so budget a $25–$50 short-term test kit on that cadence. Beyond that, no service contract or annual fee.

Will mitigation hurt my home's resale value?

The opposite — a documented mitigation system helps resale because it removes radon as an inspection blocker. In Colorado, where 46.9% of homes test above 4 pCi/L, "radon mitigation system installed" is a meaningful line item on a listing.

How long does the install take?

4–6 hours for a standard basement install. One day max. Most homeowners stay home during the work; the only time the house needs to be empty is during the 48–96-hour post-install retest, which requires closed-house conditions.

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Want the full county-by-county risk picture before you call for a quote? Get the free Colorado Radon Risk Map — same CDPHE data, summarized on one page.

Sources

• EPA, Consumer's Guide to Radon Reduction: How to Fix Your Home (EPA 402/K-10/005, 2025). epa.gov/radon
• Colorado Department of Public Health and Environment, county radon test database (2005–2024).
• Aggregated public pricing pages and homeowner-reported quotes from Colorado-based radon mitigators and Denver-area homeowners, surveyed April 2026.