If you have tested your Billings home for radon and the results came back above the EPA action level of 4.0 pCi/L, the next question is straightforward: how much will it cost to fix? The answer depends on your foundation type, the size of your home, and how elevated your radon levels are — but for most Billings homeowners, a standard mitigation system falls between $800 and $1,600.
Billings is the largest city in Montana and sits squarely in EPA Radon Zone 1, the highest-risk designation. The Northern Plains geology beneath Yellowstone County is rich in uranium-bearing soils, which produce radon gas as a natural byproduct of radioactive decay. That gas migrates upward through the ground and into homes through foundation cracks, slab joints, and utility penetrations. Montana’s cold winters compound the problem: when homes are sealed up for heating season, there is less natural air exchange to dilute indoor radon, so concentrations tend to peak between October and March. Many homes in the Billings metro test above the action level, making mitigation a common and well-understood service in this market.
This guide breaks down the real costs you can expect in 2026, what is included in a professional installation, and how to evaluate contractors before you hire.
Average Radon Mitigation Costs in Billings (2026)
The table below reflects typical pricing for professionally installed radon mitigation systems in the Billings, MT area. Actual costs vary based on your specific home and conditions.
| System Type | Low | Mid | High |
|---|---|---|---|
| Standard Sub-Slab Depressurization | $800 | $1,200 | $1,600 |
| Crawl Space System | $1,500 | $2,200 | $3,500 |
| Multiple Suction Points | $2,500 | $3,000 | $4,000 |
| Radon Testing (short-term) | $100 | $150 | $200 |
| Post-Mitigation Testing | Included | $150 | $300 |
| Fan Replacement | $300 | $500 | $800 |
The most common installation in Billings is a single-point sub-slab depressurization system for a home with a basement or slab-on-grade foundation. This is the system type that falls in the $800–$1,600 range and accounts for the majority of residential radon jobs in Yellowstone County.
Factors That Affect Radon Mitigation Cost
No two homes are identical, and the final price of your system depends on several variables that a qualified contractor will assess during an in-home inspection.
- Foundation type. Slab-on-grade and standard basements are the least expensive to mitigate. Crawl spaces require additional materials — typically a vapor barrier sealed across the entire crawl area — and significantly more labor. Combination foundations (basement plus crawl space, or split-level homes) often need separate suction points for each area, pushing costs higher.
- Number of suction points. Most homes require a single suction point drilled through the slab. Larger homes, homes with complex foundation layouts, or homes with very high radon concentrations may require two or more suction points to achieve adequate depressurization across the entire footprint.
- Radon concentration level. Higher initial readings sometimes require more aggressive system designs — larger fans, additional suction points, or supplemental sealing work — to bring levels reliably below 4.0 pCi/L.
- Home size and layout. A 1,200-square-foot ranch costs less to mitigate than a 3,500-square-foot multi-level home with finished basement space. Pipe routing, the number of floors the PVC must pass through, and accessibility all affect labor time.
- Pipe routing complexity. Ideally the PVC exhaust pipe runs from the suction point through an interior utility space and exits above the roofline. When there is no clean interior path, exterior pipe runs are necessary, which can add cost for additional fittings, paint-matching, and weatherproofing.
- Winter installation considerations. Montana winters do not prevent installation, but frozen ground and sub-zero temperatures can add minor complexity to exterior work. Scheduling during the heating season is common because that is when most homeowners discover elevated radon through testing.
What’s Included in a Professional Radon Mitigation Installation
A reputable Billings radon contractor should include all of the following in a standard mitigation quote. If any of these items are missing or listed as add-ons, ask why.
- In-home assessment and diagnostic evaluation
- Custom system design for your foundation type
- Drilling of suction point(s) through the slab
- Schedule 40 PVC pipe installation and routing
- Exterior inline fan mounting and wiring
- Sealing of visible cracks, joints, and penetrations
- System verification with manometer gauge
- Post-mitigation radon testing (24–48 hrs after install)
- Written guarantee of results below 4 pCi/L
Post-mitigation testing is the proof that the system works. Any contractor who does not include testing or a written guarantee should raise a red flag. The goal is not just to install hardware — it is to verify that your home’s radon levels are actually reduced to safe levels.
How to Choose a Radon Contractor in Billings
Radon mitigation is not a regulated trade in every state, but Montana does require contractors to follow specific guidelines. Here is what to look for when evaluating radon professionals in the Billings area.
- Montana licensing and insurance. Confirm the contractor is properly licensed and carries general liability insurance. Ask for proof of both before any work begins.
- NRPP or AARST certification. The National Radon Proficiency Program (NRPP) and the American Association of Radon Scientists and Technologists (AARST) both certify radon mitigators. These credentials indicate the contractor has passed an exam, maintains continuing education, and follows established standards of practice.
- Written guarantee of results below 4 pCi/L. This is the industry standard. If a contractor will not put their guarantee in writing, that is a problem. A credible guarantee means they will return and adjust the system at no additional charge if post-mitigation levels remain above the EPA action level.
- Post-mitigation testing included. Testing after installation is not optional — it is how you know the system works. The best contractors include it in their base price or arrange independent third-party testing.
- Local Yellowstone County experience. Billings has specific soil conditions, foundation types, and climate factors that affect system design. A contractor who has installed hundreds of systems in this market will diagnose and solve problems faster than one working from a generic playbook.
Get at least two written quotes, and compare not just price but scope — what is included, what is guaranteed, and whether post-mitigation testing is part of the package.
Frequently Asked Questions
How much does radon mitigation cost in Billings?
Most Billings homeowners pay between $800 and $1,600 for a standard sub-slab depressurization system. Crawl space systems run $1,500–$3,500, and homes requiring multiple suction points can reach $2,500–$4,000. The final cost depends on your foundation type, the size of your home, and the severity of your radon levels. A qualified contractor will provide an exact written quote after an in-home assessment.
How long does radon mitigation take?
Most residential radon mitigation systems in Billings are installed in a single day, typically 4–8 hours depending on the complexity of the job. Your home is fully livable immediately after installation — there is no curing period or off-limits area. Post-mitigation testing is performed 24–48 hours later to confirm the system has reduced radon below the EPA action level of 4 pCi/L.
Does radon mitigation increase home value in Montana?
Yes. A professionally installed radon mitigation system with documented post-mitigation test results is a selling point for Montana home buyers. Elevated radon is one of the most common issues flagged during home inspections in Yellowstone County, and a pre-existing system removes a potential deal-breaker. It demonstrates proactive maintenance and provides peace of mind that the home’s air quality has been addressed.
Can I install a radon system myself?
While DIY radon mitigation kits exist, the EPA recommends hiring a certified radon mitigator for several reasons. Improper installation can fail to reduce radon levels, waste money on undersized or incorrectly placed equipment, or create new problems such as backdrafting combustion appliances. A professional installation includes proper diagnostics, correct fan sizing for your soil conditions, sealed penetrations, and a written guarantee that the system will reduce radon below 4 pCi/L. For most homeowners, the cost difference between DIY and professional installation is not large enough to justify the risk.
When should I test for radon in Billings?
The EPA recommends testing during the heating season — October through March — when homes in Billings are sealed up and radon levels tend to be highest. That said, radon testing can be performed any time of year and still provide valuable data. Every home in Billings should be tested at least once, and the EPA recommends retesting every two years or after any major renovation. Yellowstone County sits in EPA Zone 1, the highest-risk category in the country, so testing is not optional — it is essential.
Get a Free Radon Mitigation Estimate
Rim Rock Radon provides free in-home assessments, written quotes, and guaranteed results for homeowners across Billings and Yellowstone County. One call, one day, one solution.
Call (406) 476-7479