High Radon Test Result in Minnesota: What To Do Next

The short answer first. At or above 4 picocuries per liter (pCi/L), the EPA recommends fixing your home, and between 2 and 4 it suggests considering it. One short-term test is a screen, not a verdict, so the standard next step is a confirming test before you spend money, unless a real estate deadline forces the decision. Your result is also not unusual here: Minnesota Department of Health data shows about 2 in 5 tested Minnesota homes at or above the action level.

What your number means

Below 2 pCi/L

Below the range where the EPA suggests considering action. No level is risk free, so retest every few years and after major renovations, and prefer a heating-season test for the worst-case view.

2 to 4 pCi/L

The band where the EPA says to consider fixing the home. A long-term test tells you whether your year-round average lives here or was a seasonal peak.

4 pCi/L and above

At or above the EPA action level: the EPA recommends fixing the home. Confirm with a follow-up test first unless a transaction deadline forces the decision, then get a written mitigation quote.

Source: EPA health risk of radon

Confirm before you mitigate

Radon levels swing day to day and season to season, so EPA guidance is to confirm a first high screen with either a second short-term test or a long-term test before mitigating. The higher the first reading, the less waiting makes sense. The exception is a home sale: when an inspection contingency is running, decisions get made on the licensed measurement in hand, and our real estate radon page covers how that negotiation works.

A winter number is your worst case, and that is useful

MDH's statewide monitoring shows indoor radon running higher in winter than in summer, averaging 4.6 pCi/L in winter against 3.5 in summer per the MDH radon data portal, because closed-house conditions and heating systems pull more soil gas indoors. That is why MDH recommends heating-season testing: a January result captures the exposure your home actually delivers in the months you live sealed in. A high winter reading is worth believing. A marginal one, in the 2 to 4 band, is the case where a long-term test spanning seasons earns its keep.

What fixing it costs

The Minnesota Department of Health reports typical installed costs of $1,500 to $3,000 for a mitigation system, and a properly installed system reliably brings levels down, verified by a follow-up test. The Minnesota cost guide breaks down every factor that moves a quote, and the mitigation page explains the system itself.

Who may do the work

Under Minnesota Statutes section 144.4961, anyone who mitigates radon for compensation must hold an MDH license, and every professional install carries a numbered MDH system tag. Verify any name in the official MDH license lookup before you sign; the license guide explains the whole system.

Retesting cheaply

Confirming a screen should not cost much. Many Minnesota county health departments may offer test kits at low or no cost, and what they run changes; check your county in the MDH Local Radon Contacts directory, or see the testing options on our radon testing page.

Verify Your Contractor's Minnesota Radon License

Before you hire anyone for radon work in Minnesota, check their license. The Minnesota Radon Licensing Act, Minnesota Statutes section 144.4961, requires anyone who performs radon testing, mitigation, or laboratory analysis for compensation to be licensed by the Minnesota Department of Health, and every mitigation system installed under the law must carry a numbered MDH system tag. On a paid install, a missing tag is the fastest red flag a homeowner can check. A licensed professional expects the question. Three things to ask before you sign:

Can I see your current MDH radon license, and is the company licensed too?

Will the installed system carry the MDH system tag required under the licensing law?

Will I get a written, itemized estimate and a follow-up radon test that confirms the system works?

High Radon Result Questions

Is 5 pCi/L dangerous?

It is above the EPA action level of 4 pCi/L, which is the threshold where the EPA recommends fixing the home. The EPA identifies radon as the leading cause of lung cancer among people who have never smoked and states that no level is considered risk free. Radon risk builds over years of exposure, so a 5 is not an emergency, but it is a number to confirm and then fix rather than file away.

My winter test was high but my summer test was fine. Which is right?

Both are real; they measure different conditions. Minnesota Department of Health data shows indoor radon averaging higher in winter than in summer, because closed-house conditions and heating systems draw more soil gas indoors. The winter number is closer to your worst-case exposure, and a long-term test spanning both seasons gives the truest year-round average to decide from.

How fast do I need to act on a high result?

Radon is a long-term exposure risk, not a gas leak, so you have time to do it right: confirm the reading, collect written quotes, and schedule the work. What the number does not deserve is a drawer. The confirmed level is what your household breathes every heating season until a system changes it.

Do I need a licensed professional to fix high radon in Minnesota?

Anyone you pay must be licensed. The Minnesota Radon Licensing Act, Minnesota Statutes section 144.4961, requires an MDH license for radon work performed for compensation, and every professionally installed system carries a numbered MDH system tag. A homeowner working on their own house is not barred by the law, but fan sizing, pressure-field diagnostics, and verification are where self-installs commonly fall short.