A radon home sale question usually comes up after the inspection, when a buyer has a number and a closing date. EPA's guide for buyers and sellers says the test should be designed around that deadline, and it lays out who should agree to what [1]. Iowa adds a disclosure step. Here is how the pieces fit.
What Iowa sellers must share
Iowa HHS says no state rule requires testing or mitigation during a sale [2]. But under Iowa Code chapter 543B and the Real Estate Commission's rules, a seller must disclose any known radon tests, with the date and result. The seller must also confirm giving the buyer a copy of the "Iowa Radon Home-Buyers and Sellers Fact Sheet" [2]. That fact sheet says the average indoor level in Iowa is 8.5 pCi/L [3].
How a sale test should run
EPA's guide says to test for at least 48 hours and to place the device in the lowest level the buyer could use as living space, such as a bedroom, playroom or den [1]. Any real estate test should include steps to prevent or detect tampering with the device [1].
In Iowa, a person testing someone else's home for pay must be certified by the state [4]. Iowa HHS posts the list of certified measurement specialists [5]. A certified tester may give results to a buyer who paid for the test, under Iowa Code 136B.2 [4].
Put it in the contract
EPA suggests the contract spell out where the test goes, who runs it, what type it is and when it happens. It should also say how buyer and seller share results and costs, and when a fix happens and who pays [1]. If the result is high, EPA says buyer and seller should talk about the timing and cost of the fix [1].
HomeGuide says the seller typically pays for a system, but that it's negotiable because the seller usually isn't legally required to [6]. National 2026 install ranges are on the radon mitigation cost page.
Timing a fix before closing
Iowa's mitigation rule gives the window for the post-mitigation test: no sooner than one day after the work and within 30 days of installation [7]. A short-term retest can take a few days, so leave room before closing. If the house already has a system, EPA tells buyers to ask the seller for test results, including who ran the last test and where [1].
FAQ
The seller tested last year. Is that enough?
EPA says to check who ran it, where in the house it was placed, and the result before you accept it [1].
Do I have to fix it to sell?
Iowa HHS says no state rule requires mitigation in a sale. The disclosure rule still applies [2].
Get a quote
On a deadline? Send your test result and closing date.
We're a referral service, not a contractor. We send mitigation requests only to contractors on Iowa HHS's current credentialed list and testing requests only to state-certified radon measurement specialists, but we don't otherwise vet them, a referral is not an endorsement, and independent contractors may pay us for referrals.
Sources
- U.S. EPA, Home Buyer's and Seller's Guide to Radon, EPA 402/K-24/001 (revised March 2024, PDF). https://www.epa.gov/sites/default/files/2015-05/documents/hmbuygud.pdf
- Iowa HHS, Radon Resources (fetched Nov 11, 2026). https://hhs.iowa.gov/health-prevention/providers-professionals/radiological-health/radon/radon-resources
- Iowa HHS (as IDPH), Iowa Radon Home Buyers and Seller Fact Sheet, dated 2/2020 (PDF). https://hhs.iowa.gov/media/7917/download?inline
- Iowa Code chapter 136B, Radon Control (2026). https://www.legis.iowa.gov/docs/code/136B.pdf
- Iowa HHS, Radon program page (fetched Nov 11, 2026). https://hhs.iowa.gov/health-prevention/providers-professionals/radiological-health/radon
- HomeGuide, "How Much Does a Radon Mitigation System Cost? (2026)," Kristen Cramer, Feb 5, 2026. https://homeguide.com/costs/radon-mitigation-cost
- Iowa Administrative Code 641, Chapter 44, Radon Mitigation (ARC 0290D, IAB 5/13/26, effective 7/1/26). https://www.legis.iowa.gov/docs/iac/chapter/641.44.pdf