How to Find a Certified Radon Professional in Colorado

Colorado Requires State Licensing

Colorado is one of a minority of states that mandates licensing for radon professionals. You cannot legally test or mitigate radon for compensation in Colorado without holding a valid credential issued through the Colorado Department of Public Health and Environment (CDPHE). This matters for homeowners because it gives you a concrete way to verify anyone you are considering hiring before they set foot in your home.

With 428 certified radon professionals listed in our Colorado directory, the most in the country, you have real choices. But the number of options makes knowing how to evaluate them more important, not less. Price differences between contractors can be significant, and the quality of testing equipment, mitigation design, and follow-through varies. This guide walks you through the Colorado licensing system, what certifications mean, how to find coverage in your area, and the specific questions to ask before signing anything.

Browse 428 certified radon professionals in Colorado in our directory.

Colorado's Licensing Requirements

Radon professional licensing in Colorado is governed by the Colorado Revised Statutes, Section 25-11-501 et seq. CDPHE administers the program and maintains the official list of licensed professionals. All radon testers and mitigators operating in Colorado must hold certification from one of two nationally recognized bodies: the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).

Both certification programs require passing a written exam, completing approved training hours, and demonstrating hands-on proficiency. Both require continuing education to maintain the credential. CDPHE accepts either, and there is no meaningful practical difference for homeowners; both pathways produce qualified professionals.

The relevant certification categories in Colorado are:

RT (Radon Tester): Licensed to perform radon measurement services. This is the credential your inspector should hold for a pre-purchase or diagnostic test.
RMT (Radon Mitigation Technician): Licensed to install and service radon mitigation systems under the supervision of an RMS.
RMS (Radon Mitigation Specialist): The full mitigation credential. An RMS can design, install, and certify mitigation systems independently. For any mitigation project, you want either an RMS or an RMT working under one.

How to Verify a Colorado Radon License

CDPHE maintains an online verification portal where you can look up any licensed professional by name or certification number. Before you hire anyone, confirm their license is active and covers the type of work you need. Testing and mitigation require different credentials, and a tester's license does not authorize mitigation work. The CDPHE verification portal is at cdphe.colorado.gov/radon.

Verification takes about two minutes. Do it before your first call, not after the contractor has already given you a quote.

NRPP vs. NRSB: What the Two Certification Bodies Are

Both the NRPP and NRSB are nationally recognized certification programs for radon professionals. The NRPP is operated by the American Association of Radon Scientists and Technologists (AARST). The NRSB is an independent credentialing organization. Both are accepted by CDPHE and by most state programs across the country.

For homeowners, the distinction between the two is less important than confirming that the professional holds a current, valid credential from either one. Both require recertification on a regular cycle, so an active credential means the professional has kept up with continuing education requirements and has not had their certification revoked.

When a contractor tells you they are certified, ask for the specific certification number. You can then verify it in the CDPHE portal. Any legitimate professional will provide this without hesitation.

Where to Find Radon Professionals Across Colorado

Colorado's 428 certified professionals are not distributed evenly across the state. Coverage density reflects population and historical demand. Knowing your area's coverage situation helps you plan accordingly.

Dense Coverage: Front Range Metro Areas

The Denver metro area, Colorado Springs, Fort Collins, and Boulder have the most radon professionals per capita in the state. In these areas, you can typically get a testing appointment within a week and a mitigation installation scheduled within two to four weeks. Competition among contractors keeps prices closer to the state average of $125 to $300 for testing and $800 to $2,500 for mitigation. Getting multiple quotes is straightforward.

Key metro submarkets with strong coverage:

Denver, Aurora, Lakewood, Centennial, Littleton, Englewood
Colorado Springs, Fountain, Monument, Pueblo (Pueblo has moderate coverage)
Fort Collins, Loveland, Greeley
Boulder, Longmont, Broomfield, Westminster

Moderate Coverage: Secondary Cities

Grand Junction and the Grand Valley have a smaller pool of certified professionals serving the Western Slope. Greeley and the northeastern plains are similarly served. In these areas, scheduling a week or two in advance is typical, and contractor choices are narrower. Pricing tends to be comparable to the Front Range.

Limited Coverage: Mountain Towns and the Western Slope

High mountain communities, including Aspen, Vail, Breckenridge, Steamboat Springs, Glenwood Springs, and Durango, have significantly fewer licensed professionals serving them. Several factors compound this:

Many of these communities are seasonal, so demand is variable and some contractors only serve them part of the year
Travel fees are common when a professional drives from Denver or the Front Range, adding $100 to $300 or more to the base cost
Scheduling lead times can be four to eight weeks during busy periods, particularly spring real estate season
Mountain home construction, often built into hillsides or on engineered foundations, can complicate mitigation design and increase installation costs beyond the typical range

If you own or are buying property in a mountain community, contact professionals early. Do not wait until a real estate transaction is already in progress to discover that the earliest available tester is six weeks out.

What to Ask Before Hiring

Once you have a list of candidates, these questions will help you separate qualified professionals from those who cut corners.

Credentials and Insurance

What is your CDPHE certification number? Verify it in the state portal. This is non-negotiable.
Do you carry general liability insurance and errors & omissions coverage? General liability covers property damage during the job. E&O covers you if the mitigation system fails to perform as specified and you suffer damages as a result. Ask for a certificate of insurance, not just a yes answer.

Equipment and Process

What equipment do you use for testing? Continuous Radon Monitors (CRMs) provide hour-by-hour readings over the test period and are less susceptible to tampering than passive charcoal canisters. For a real estate transaction, many inspectors use CRMs because the data log documents that test conditions were maintained throughout.
What fan brands and models do you use for mitigation? Reputable installers use fans from established manufacturers such as RadonAway, Festa, or Fantech. They should be able to explain why they chose a particular model for your home's configuration.
Will you provide a written quote with all materials and labor itemized? A written quote protects you from add-on charges after installation begins. If a contractor is reluctant to put the scope and price in writing, that is a problem.

After the Job

What warranty do you offer on the mitigation system? A standard warranty covers both parts (fan) and labor for one to two years. Fan manufacturers typically provide longer warranties on the equipment itself. Get the warranty terms in writing.
Is a post-installation test included? A post-mitigation test confirms the system is actually reducing levels below 4 pCi/L. Reputable contractors include this as part of the job. Some provide a short-term CRM test immediately; others set a charcoal canister for 48 to 96 hours. Either is acceptable. If a contractor considers the job done without post-testing, look elsewhere.
Will you pull required permits? Most Colorado municipalities, including Denver, Aurora, Colorado Springs, Fort Collins, and Jefferson County jurisdictions, require a permit for radon mitigation system installation. A professional who skips permitting is exposing you to potential issues when you sell the home. Ask before the job starts.

Red Flags in Colorado's Radon Market

Colorado's high radon awareness creates demand, and where there is demand, there are contractors willing to cut corners. Watch for these warning signs.

Unlicensed Contractors

This is the clearest disqualifier. Operating without CDPHE licensure is illegal in Colorado. An unlicensed contractor has not demonstrated minimum competency, carries no accountability to the state program, and gives you no recourse if the work is defective. Verify the license number in the CDPHE portal before any conversation goes further.

Testing and Mitigation Combined in One Visit

In a real estate transaction, having the same company perform the initial diagnostic test and the mitigation creates a conflict of interest. A company that will earn $1,500 from a mitigation job has a financial incentive to recommend mitigation. AARST's protocols address this by recommending independent testing for real estate purposes. For non-transactional testing on a home you already own, this is less of a concern, but it is worth being aware of.

No Post-Installation Test

Any contractor who considers the mitigation complete without a post-installation test is either cutting corners or does not understand the standard. Mitigation reduces radon in most homes, but the reduction amount depends on system design, fan sizing, and installation quality. The post-test is the proof. Without it, you do not know if the system worked.

Vague Lifetime Guarantees

Some contractors advertise “lifetime guarantees” on their mitigation systems. Read the fine print before letting this influence your decision. A meaningful guarantee specifies what is covered (parts, labor, or both), what radon level the system is guaranteed to achieve, and how claims are handled. A “lifetime guarantee” that covers nothing specific is a marketing phrase, not a commitment.

Typical Costs in Colorado

Having a benchmark helps you evaluate quotes. Colorado pricing in 2026:

Radon testing: $125 to $300 for professional testing. Short-term tests (48 to 96 hours) are at the lower end; long-term tests (90 days to 1 year) cost more but give more reliable data for non-transactional decisions.
Radon mitigation: $800 to $2,500 for a standard sub-slab depressurization system in the Front Range and metro areas. Multiple suction points, complex foundation types, or crawl space work can push costs higher.
Mountain town premium: Expect travel fees and potentially higher installation costs in Aspen, Vail, Breckenridge, Steamboat Springs, and similar locations. Total mitigation cost in these areas can reach $3,000 to $4,500 depending on location and foundation complexity.

Getting two or three quotes for mitigation is practical in metro areas where contractor density is high. In mountain communities, your options may be narrower, but even a single detailed written quote gives you a basis for evaluating whether the scope of work is appropriate.

Start With the Directory

Our Colorado directory lists 428 CDPHE-certified radon professionals organized by location. You can search by city or county to find licensed testers and mitigators serving your area, with direct contact information and credential details.

Browse 428 certified radon professionals in Colorado and find someone serving your area today.

Frequently Asked Questions

Does Colorado require a license for radon testing and mitigation?

Yes. Colorado law under CRS Section 25-11-501 et seq. requires all radon testers and mitigators operating for compensation to hold certification from NRPP or NRSB and be licensed through CDPHE. You can verify any professional's license at cdphe.colorado.gov/radon.

What is the difference between NRPP and NRSB certification?

Both are nationally recognized radon professional certification programs. NRPP is operated by AARST (American Association of Radon Scientists and Technologists). NRSB is an independent credentialing organization. Both require passing exams, training hours, and ongoing continuing education. Colorado's CDPHE accepts either. For homeowners, the practical difference is minimal; confirm the specific credential is current using the state verification portal.

How much does radon mitigation cost in Colorado?

Standard sub-slab depressurization systems in Front Range and metro areas typically cost $800 to $2,500. Mountain communities such as Aspen, Vail, and Breckenridge often cost more due to travel fees and complex foundation situations, sometimes reaching $3,000 to $4,500. Professional testing runs $125 to $300 before mitigation.

How do I find a radon professional in a Colorado mountain town?

Coverage in high-altitude communities including Aspen, Vail, Breckenridge, Steamboat Springs, and Glenwood Springs is limited. You may need to book four to eight weeks in advance, and some professionals travel from the Front Range and charge travel fees. Search our Colorado directory filtered by county and contact professionals early, especially if you have a real estate transaction deadline.

What should be included in a radon mitigation job in Colorado?

A complete mitigation job should include a written quote with itemized materials and labor, a permit pulled from your municipality (required in most Colorado jurisdictions), installation of the sub-slab depressurization system, and a post-installation radon test confirming the system reduced levels below 4 pCi/L. Warranties covering the fan and labor for at least one year are standard. Any contractor who considers the job done without a post-installation test is not following proper practice.