Verify Certified Radon Mitigation Contractors (2026 Guide)

Hiring a radon mitigation contractor without checking their NRPP status is like hiring an electrician without checking a license — the work might look fine until it doesn't. This guide walks through exactly how to confirm certified radon mitigation credentials before a crew touches your home.

TL;DR

Verify certified radon mitigation status directly on the NRPP or NRPP-recognized database before signing a contract in 2026.
Match the certification type to the job — a Measurement Specialist can’t legally install a mitigation system.
Confirm the license hasn’t lapsed; NRPP credentials expire and require continuing education to renew.
Michigan Radon Control holds NRPP certification for both testing and mitigation work across Metro Detroit and Lansing.

Why this matters

Radon mitigation isn't a cosmetic fix. A poorly sealed sub-slab depressurization system can leave radon levels above the EPA action level of 4.0 pCi/L while giving homeowners false confidence that the problem is solved.

Anyone can call themselves a "radon guy" and pull a permit in most Michigan municipalities. NRPP certification is the actual proof that a contractor passed an exam, carries continuing education credits, and follows AARST-ANSI installation standards. Skipping the verification step is the single most common mistake homeowners make when comparing radon mitigation for home sellers before listing or new homeowners fixing an issue found at closing.

For a full rundown of vetted local options, the best radon mitigation contractors in Metro Detroit guide breaks down who holds active credentials as of 2026 versus who doesn't.

What you'll need

The contractor's full legal business name and the individual technician's name
Their NRPP ID number (a good contractor lists it on their proposal, website, or truck signage)
10 minutes and internet access
A copy of the proposed contract or estimate
The address of the property being mitigated

The steps

1. Ask for the NRPP ID number directly

Don't accept "we're certified" as an answer — ask for the number. Every legitimately certified radon mitigation professional has an ID they can produce instantly, usually printed on their business card or an EPA-style credential card.

A contractor who hesitates or can't locate the number on the spot is a red flag worth walking away from. This step alone eliminates most bad actors before you waste time on the rest of the process.

Common mistake: accepting a state contractor license number as a substitute. General contractor licensing and radon certification are two separate systems.

2. Search the certification in the national database

NRPP maintains a searchable directory of every active certificate holder by name, company, or ID number. Cross-reference the name on the estimate against the name in the database — mismatches happen when a company subcontracts the actual install crew.

This step confirms the person doing the work, not just the company selling the job, is certified radon mitigation personnel.

Common mistake: verifying only the salesperson's credentials and never checking the installer who shows up on install day.

3. Confirm the certification type matches the scope of work

NRPP issues separate credentials for testing (Radon Measurement Specialist) and installation (Radon Mitigation Specialist). A tester certified only in measurement has no business quoting or installing a sub-slab depressurization system.

Check the listing type in the directory result. It will say explicitly which category the credential covers, and whether it's residential, multifamily, or school-and-large-building scope.

Expected outcome: you should see "Mitigation" listed for any contractor bidding on install work, not just "Measurement."

4. Check the expiration date

NRPP certifications aren't permanent — they lapse without renewal and continuing education. A directory listing showing an expired date in 2024 or 2025 means the contractor is currently unqualified to advertise as certified radon mitigation, even if they held the credential in the past.

This is the step people skip most often because they assume certification is a one-time event.

Common mistake: relying on a printed certificate from a prior year instead of the live database, which reflects real-time status.

5. Verify insurance and workers' comp coverage separately

NRPP certification proves technical competence, not liability coverage. Ask for a certificate of insurance naming general liability and, if the contractor has employees, workers' comp.

A radon fan install involves roof penetration, electrical work, and sometimes crawl space or slab drilling — all activities where an uninsured contractor puts the homeowner at financial risk if something goes wrong.

Expected outcome: a certificate of insurance document, not a verbal assurance.

6. Ask how the post-installation test will be conducted

A certified radon mitigation installer should test the finished system before calling the job complete, confirming levels dropped below the EPA action level. Ask what device they use and how long the follow-up test runs — a rushed 48-hour test right after installation without settling time can produce misleading readings.

Homeowners preparing for a sale should read how to verify your radon mitigation system is still working to understand what ongoing verification looks like after install day too.

Verify before you hire

Confirm NRPP-certified mitigation and get a written estimate for Metro Detroit or Lansing.

Get an estimate

7. Get the certification number written into the contract

Once verified, require the NRPP ID number appear on the signed proposal alongside the technician's name. This protects you if a dispute arises later and gives you a paper trail tied to a specific certified individual, not just a company name.

Troubleshooting

The name in the directory doesn't match the business name on the estimate. Ask directly whether the work is subcontracted, and get the actual installer's ID before signing.

The certification shows "expired" but the contractor says it's renewing. Get the renewal confirmation in writing or wait until the directory reflects active status — a pending renewal isn't a current credential.

The contractor only has a Measurement certification, not Mitigation. They can test your home, but they cannot legally design or install a mitigation system under NRPP standards. Bring in a separately certified installer.

Two contractors quote wildly different system designs for the same house. This usually signals one of them skipped a proper diagnostic, especially on trickier layouts covered in radon mitigation systems for crawl space homes or homes with sump pits.

The estimate has no mention of a post-mitigation test. Ask why — a legitimate installer builds retesting into the scope of work by default in 2026, not as an upsell.

You can't find any record of the contractor in the database at all. Treat this as disqualifying. No listing means no active certified radon mitigation credential, regardless of what's printed on their truck.

Tools and resources

NRPP's public certification lookup (search by name, company, or ID)
A written estimate that names the installing technician
How to budget for a radon mitigation system installation for cost context before comparing quotes
Radon mitigation system installation for Michigan homes to understand what a compliant install actually includes
A certificate of insurance request template (ask any contractor to provide one)

What to do next

Once you've confirmed certification, the next decision is system type — not every home needs the same mitigation approach. Homes with finished basements, slab-on-grade foundations, or sump pumps each call for a different design, and a certified installer should be able to explain which applies to your house and why before quoting a price.

FAQ

How do I verify certified radon mitigation status for a contractor?

Search the contractor’s name or NRPP ID number in the national NRPP certification directory and confirm the listing is active and covers mitigation, not just measurement. Cross-check the expiration date since credentials lapse without renewal.

Is NRPP certification required by law in Michigan?

NRPP certification is the industry-standard credential recognized across most states, and it’s the qualification homeowners and real estate transactions typically require to trust a mitigation installation. Always confirm current requirements with the contractor directly.

What’s the difference between a Measurement Specialist and a Mitigation Specialist?

A Measurement Specialist is certified to conduct radon testing only. A Mitigation Specialist is certified to design and install reduction systems, and the two credentials are not interchangeable.

How much does certified radon mitigation cost in 2026?

Costs vary by home layout, foundation type, and system complexity. The budgeting breakdown at michiganradoncontrol.com covers typical ranges by home configuration.

Do NRPP certifications expire?

Yes, NRPP certifications expire and require continuing education credits to renew. A directory listing showing a past expiration date means the contractor is not currently certified, regardless of past credentials.

Can a general contractor install a radon mitigation system without NRPP certification?

General contracting licenses and NRPP radon certification are separate systems, and a general contractor’s license does not substitute for radon-specific certification. Ask for the NRPP ID directly before hiring.

What happens if my mitigation system was installed by an uncertified contractor?

An uncertified install carries higher risk of design errors, such as insufficient suction or improper sealing, that leave radon levels above the EPA action level of 4.0 pCi/L. Retesting and possibly re-installation may be needed.

Where can I find NRPP-certified radon mitigation contractors near me?

Search the NRPP directory by ZIP code or check a local guide like the best radon mitigation contractors in Metro Detroit list, which tracks which local companies currently hold active credentials.

One last thing

The expiration date is the detail almost everyone misses. A contractor can genuinely have earned NRPP certification years ago, show you a real certificate, and still be operating unlicensed today because the credential lapsed and was never renewed — the printed paper doesn't update itself, only the live database does.