If you’re buying a home anywhere in the Twin Cities this year, radon belongs on your checklist right next to the furnace, the roof, and the foundation. Radon in Minnesota isn’t a rare, worst-case problem. It’s common, it’s invisible, and it shows up in brand-new builds in Plymouth just as easily as 1920s bungalows in South Minneapolis. The good news is that it’s easy to test for, Minnesota has clear disclosure rules, and fixing it is usually a one-day job. Here’s what every buyer (and seller) should know in 2026.

Why Radon in Minnesota Is a Bigger Deal Than Most Buyers Expect

Radon is a naturally occurring radioactive gas that seeps up from the soil and into homes through foundation cracks, sump pits, floor drains, and gaps around pipes. You can’t see it, smell it, or taste it. Our glacial soils make this state a hot spot: according to the Minnesota Department of Health, more than two in five homes here have radon at levels that pose a significant health risk, and the average level statewide runs more than three times the national figure.

Why does that matter? Radon is the leading cause of lung cancer among nonsmokers. And Minnesota living makes exposure worse in a very specific way: we keep our homes sealed up tight for five or six months a year, and many of us spend a lot of that time in finished basements, which is exactly where radon levels tend to be highest. Your neighbor’s test results also tell you very little. Two houses on the same Edina block can test completely differently, so the only way to know is to test the home you’re buying.

What Minnesota’s Radon Disclosure Rules Actually Require

Since January 1, 2014, the Minnesota Radon Awareness Act (Minn. Stat. § 144.496) has required sellers of residential property to disclose what they know about radon before a purchase agreement is signed. Those rules are unchanged heading into 2026. In writing, the seller must share:

• Whether the home has ever been tested for radon
• The most current test records and results
• Any mitigation or remediation that’s been done
• Information and documentation on any installed mitigation system
• A required radon warning statement, plus a copy of the MDH publication Radon in Real Estate Transactions

Here’s the part that surprises a lot of buyers: the law does not require anyone to test. Sellers only have to disclose what they already know. If they’ve never tested, the disclosure simply says so. If a seller knowingly hides radon information, a buyer can take legal action within two years of closing. Also note that some sales are exempt, including foreclosures and transfers to heirs, so if you’re eyeing a bank-owned or estate property, you may get no radon disclosure at all. For more on the broader disclosure picture, our buyer resources walk through what to expect in a Minnesota transaction.

How to Test for Radon When You’re Buying a Home

Because testing isn’t automatic, it’s up to you to build it into your offer, usually alongside your home inspection contingency. MDH’s real estate radon guidance lays out how a proper test should be done:

• Use a licensed pro. Under the Minnesota Radon Licensing Act, anyone testing a home they don’t own or rent must be licensed by MDH. Many home inspectors carry the license and can run the test during your inspection.
• Test for at least 48 hours. That means a calibrated continuous radon monitor or two short-term kits placed side by side.
• Keep the house closed up. Windows and doors stay shut except for normal coming and going, with heating or cooling running as usual.
• Test the lowest livable level. In most Twin Cities homes, that’s the basement.

Timing matters. A 48-hour test plus results can eat up a good chunk of a short inspection window, so get it scheduled the day your offer is accepted. And yes, test new construction too. Minnesota has required new homes to be built radon-resistant since 2009, but the standard setup is a passive pipe with no fan. It helps, but it doesn’t guarantee a low reading. The upside is that if levels come back high, adding a fan to an existing passive system is usually simpler and cheaper than starting from scratch.

Selling? MDH notes that sellers can benefit from testing before listing. A pre-listing test lets you mitigate on your own timeline instead of negotiating under pressure mid-deal. Our seller resources cover other ways to get ahead of inspection surprises.

Radon Mitigation Costs in Minnesota (and Who Pays)

If the test comes back at or above 4 pCi/L, MDH recommends installing a mitigation system. Between 2 and 4 pCi/L, it’s worth considering. According to MDH’s mitigation guidance, costs generally range from $1,500 to $3,000, depending on how the home is built and which type of system it needs:

• Sub-slab suction – the most common setup for basement and slab homes
• Drain tile suction – uses an existing drain tile system to pull radon away
• Sub-membrane – for crawl spaces, sealing a membrane over the soil

All three work the same basic way: a fan runs continuously, pulling radon from beneath the home and venting it out a pipe above the roofline. A well-installed system should bring levels below 4 pCi/L, and often below 2. Mitigators must be MDH-licensed and attach an MDH tag to finished systems, and most installs need an electrical permit for the fan. Once it’s running, wait at least 24 hours and retest to confirm it’s working.

Who pays is negotiable, and a high radon result rarely needs to kill a deal. Common outcomes include the seller installing a system before closing, a closing credit so the buyer can hire their own mitigator, or a price adjustment. If the home already has a system, ask for the documentation, look for the MDH tag, and know that MDH offers a free inspection for systems installed after June 2020.

Radon in Minnesota: Quick Answers to Common Questions

Do Minnesota home sellers have to test for radon?

No. Sellers must disclose any radon testing, results, and mitigation they know about, and provide the required MDH publication, but they aren’t required to test. Testing is the buyer’s call.

Should I walk away from a house with high radon?

Usually not. Elevated radon is common here and is one of the more predictable fixes in a home purchase. A typical system costs $1,500 to $3,000 and can be installed quickly, so most buyers negotiate a fix or credit rather than walking.

Do newer homes still need a radon test?

Yes. Homes built since 2009 include radon-resistant features, but most use a passive system without a fan. Testing tells you whether that’s enough or whether a fan upgrade makes sense.

The Right Agent Makes Radon a Non-Event

Handled well, radon is a line item, not a crisis. The difference usually comes down to your agent: someone who writes testing into your offer, keeps the inspection timeline on track, and knows how to turn a high reading into a fair fix or credit without derailing the deal. Experienced local agents deal with radon in Minnesota on nearly every transaction, from Prior Lake to Wayzata.

That’s exactly the kind of agent MinnMatch connects you with. We personally match buyers and sellers with vetted Twin Cities agents who know the local details, and it’s free. See how our matching works, or find your agent and walk into your next home purchase with one less thing to worry about.