The Minnesota Radon License Guide
Minnesota is one of the few states that licenses radon work, and most homeowners find out only after signing a contract. This guide explains what the Minnesota Radon Licensing Act requires, who must hold a license from the Minnesota Department of Health, what the system tag on a finished installation means, and how to verify any contractor in the official lookup in under a minute.
The law: Minnesota Statutes section 144.4961
The Minnesota Radon Licensing Act took effect for licensing purposes on January 1, 2019. From that date, every person, firm, or corporation that performs a service for compensation to detect radon, analyze radon samples in a laboratory, or mitigate radon in the indoor atmosphere must hold an annual license from the Minnesota Department of Health. MDH also adopted work standards under the law, so a license carries real obligations about how systems get designed, installed, and documented, not just a fee.
The phrase that matters is for compensation. The law regulates people you pay. A homeowner working on their own house is outside it, but anyone quoting you money for radon work is squarely inside it.
The three licenses you will encounter
Radon measurement professional
Licensed to test for radon for compensation: home sale measurements, post-mitigation verification, and professional monitoring all fall here.
Radon mitigation professional
Licensed to design and install mitigation systems in buildings the person does not own, or to provide on-site supervision of mitigation work and technicians.
Radon mitigation company
The business entity itself holds a company license in addition to the individual professional licenses of the people signing off on the work.
One practical consequence: on a mitigation job you should be able to match two names in the state lookup, the individual mitigation professional responsible for your install and the company on your contract. MDH lists both in its directory of licensed mitigation professionals and its directory of measurement professionals.
The system tag: proof that outlives the job
Under section 144.4961, every radon mitigation system installed in Minnesota on or after January 1, 2019 must carry a system tag provided by the commissioner of health, attached by the mitigation professional in a visible location, usually on the pipe near the manometer. The tag matters twice: on installation day it confirms a licensed professional stands behind the work, and years later it answers the question every buyer and inspector asks about who installed the system. When you sell, the tagged system slots cleanly into the radon disclosure Minnesota requires under the Radon Awareness Act.
How to verify a license, step by step
- 1 Open the MDH radon licensing site at radon.web.health.state.mn.us and choose the service provider search.
- 2 Select the license type you are checking: measurement professional, mitigation professional, or mitigation company.
- 3 Search by name or location, then match both the individual professional and the company name on your quote.
- 4 Confirm the license is current for this year. Minnesota radon licenses renew annually.
Three questions that sort contractors fast
- Can I see your current MDH radon license, and is the company licensed too? A licensed professional answers instantly.
- Will the installed system carry the MDH system tag? Anything other than an immediate yes is a warning.
- Will I get a written, itemized estimate and a follow-up radon test that verifies the result? Both are standard practice for licensed professionals.
If someone offers unlicensed radon work
Decline, and report it if you want to protect the next homeowner. The MDH Indoor Air Unit administers the licensing program and takes questions and complaints at health.indoorair@state.mn.us or 651-201-4601. Every contractor a homeowner reaches through this site is expected to hold current MDH licensing, and we encourage you to verify independently in the lookup no matter how you found the company. That double-check culture is the point of the law.
Ready for numbers instead of paperwork? The Minnesota radon mitigation cost guide covers what licensed installs run, and our radon mitigation page walks through the system itself. For local context, see how licensing plays out in border markets on the Duluth and Moorhead pages.