The state rules
From Minnesota Statutes 144.4961 and the MDH radon licensing page, read 23 October 2026:
| Rule | Detail |
|---|---|
| License required | "Effective January 1, 2019, a license is required annually" for radon detection, lab analysis or mitigation done for compensation (subd. 5) |
| Mitigation professional license | $250 a year |
| Mitigation company license | $100 a year; waived if the company employs only one licensed mitigation professional |
| Measurement professional license | $150 a year |
| System tag | Required on systems installed on or after 1 January 2019; the professional "must attach the tag to the radon mitigation system in a visible location"; $75 per tag |
| Owners | MDH: no license needed for "Installing a mitigation system in a building that you own or lease" |
| Law passed | Signed in May 2015 |
The tag is the thing a homeowner can check. After the install, look for the MDH tag on the vent pipe; a pro-installed system from 2019 on without one was installed outside the rules. MDH's Indoor Air Unit (651-201-4601, health.indoorair@state.mn.us) answers license questions; licenses are kept in its Radon Licensing System.
What to ask before you hire
- The mitigation professional's MDH license number, and the company license unless they work alone.
- That the quote includes the $75 state tag and who files it.
- Whether the job needs a Saint Paul permit, and that the contractor pulls it. Radon mitigation is its own category in the City's permit file, with 162 permits in three years.
- A post-mitigation test. The statute covers measurement as a licensed activity too, so the follow-up test should come from a licensed measurement professional or a device from a licensed lab.
What Saint Paul's radon permits show
| Measure | Saint Paul radon mitigation |
|---|---|
| Permits on homes, October 2023 to September 2026 | 162 |
| Firms | 38 |
| Usual filed value | $1,000 |
| Middle half of firms' usual value (3+ permits) | $1,000 to $1,600 |
| Reached final (permits a year or more old) | 62.4% |
| Usual days from issue to final | 245 |
| Share held by the busiest firm / five busiest | 37.0% / 64.2% |
| Firms with one permit only | 23 (60.5%) |
| Busiest / quietest month | September (193) / August (37) |
This is a concentrated, slow-closing trade. The busiest firm, Elander Mechanical Inc, holds 37.0% of the permits, and 60.5% of firms on the list filed just one. Permits that close take a long time: the usual one reached final 245 days after issue, and only 62.4% of those a year or more old closed at all. Ask who books the final inspection, and keep the test result and the tag photo with your house papers.
See every Saint Paul radon mitigation firm →
Prices by firm: Saint Paul radon mitigation cost. Several of the busiest radon firms here are plumbing companies; compare them on Saint Paul plumbers. License lookups for other trades: check a contractor license in Minnesota. Totals by year: Saint Paul permit statistics. Selling? Saint Paul's Truth-in-Sale of Housing report is a separate requirement.
What this does not tell you
Our list counts City permits, not MDH tags, so a mitigator who installs without a City permit is invisible here, and our license match is to state trade licenses, not MDH radon licenses. With 162 permits, one busy year at one firm moves every figure in the table.
How we know this
License dates, fees and the tag rule are from Minnesota Statutes 144.4961 (2024 edition) and the MDH radon licensing page, read 23 October 2026. Permit counts are City of Saint Paul permits classified as radon mitigation on homes, October 2023 to September 2026; finished share uses permits a year or more old, and days to final is the median from issue to final.
Numbers come from City of Saint Paul building and trade permits (the City's old approved-permits file up to June 2025, and the City's PAULIE permit system since September 2025), with the contractor named on each permit, data through October 22, 2026. Nobody paid to be on this page and nobody can.
Questions
- Does a radon mitigation contractor need a license in Minnesota?
Yes. Minnesota Statutes 144.4961 says that effective 1 January 2019 a license is required annually for anyone who does radon mitigation for pay. The mitigation professional license is $250 a year and a mitigation company license $100 (waived for a company with only one licensed professional).
- What is a Minnesota radon mitigation system tag?
A tag issued by the Minnesota Department of Health that the licensed mitigation professional must attach to the system in a visible place. It is required on systems installed on or after 1 January 2019 and costs $75 per tag.
- Can I install my own radon system in Saint Paul?
The state license is not needed to install a mitigation system in a building you own or lease, per the Minnesota Department of Health. Ask Saint Paul's Department of Safety and Inspections what City permit the work needs before you start; radon mitigation is a permit category in the City's file.
- How much does radon mitigation cost in Saint Paul?
The usual radon mitigation permit in our Saint Paul data was filed at $1,000, and the middle half of firms' usual values ran $1,000 to $1,600. Filed values are the contractor's estimate, not the invoice.
- When do Saint Paul radon contractors file the most permits?
In September (index 193, where 100 is an average month). The quietest month is August (37).
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- How to check a contractor's license in Minnesota
- What's a good completion rate for a contractor? The benchmarks from 12 trades and cities
- Contractor red flags, including the three you can see in the public record
- Detached garage cost: what garage permits show in 16 cities
For one city
- Minnesota Statutes § 144.4961 Minnesota Radon Awareness and Protection Act (2024) (accessed 2026-10-23)
- Radon licensing — Minnesota Department of Health (accessed 2026-10-23)