Wisconsin Department of Health Services
Wisconsin radon (air)
No state license roster to republish. Updated 2026-09-05 (US/Pacific).
If you are not sure you need a pro yet, see when a DIY radon test kit is enough or how to test a home for radon.
Wisconsin does not require radon measurement or mitigation contractors to be state licensed or nationally certified and does not publish a public statewide list of those businesses. This page does not invent company names, phones, licenses, or addresses to fill that gap.
DHS recommends finding a radon professional through an EPA-recognized credentialing body: NRPP or NRSB (the same organizations DHS names on its “How to Find a Contractor” page). Filter by measurement vs. mitigation, then re-check the credential before hiring.
What DHS says homeowners can do
- About 1 out of 10 homes in Wisconsin has high radon levels. You cannot see or smell radon — testing indoor air is the only way to know a building’s level.
- EPA’s long-term action level remains 4 pCi/L. DHS recommends every home and building be tested.
- Test kits are widely available; many regional Radon Information Centers provide kits free or at reduced cost. Start from the DHS radon hub and the testing guidance linked there.
- DHS publishes an interactive map of past test results for context only — it is not a substitute for testing your own home.
- Questions or kit help: call 1-888-LOW-RADON (1-888-569-7236) or contact your regional Radon Information Center (linked from the DHS radon pages).
Official sources
- Wisconsin DHS — Radon: How to Find a Contractor (retrieved 2026-09-05; page last revised January 2, 2025)
- Wisconsin DHS — Radon Information (retrieved 2026-09-05; page last revised July 6, 2026)
- NRPP Find a Pro (linked from DHS for measurement and mitigation)
- NRSB find a professional (linked from DHS for measurement and mitigation)
- U.S. EPA Radon
This index does not rank contractors or take referral fees. No Amazon kit links on this state page.