How we build listings
- Credential data comes from public state and national lists, re-checked on a schedule. Each listing shows the date it was last checked.
- Details like services, warranty length and posted prices come from the installer’s own website, with a link to the page.
- If we couldn’t find something, we leave it blank. We never estimate an installer’s price.
- RadonCosts is independent. Installers can’t pay to change their credential status or homeowner reports.
Sources
Retrieved Nov 2, 2026 unless noted. Pages on this site cite these sources with short IDs in brackets, for example [EPA-1]. Each ID links to its row below. Estimates are marked “(estimate)”.
| ID | Source | Link |
|---|---|---|
| EPA-1 | US EPA, Health Risk of Radon (21,000 deaths/yr estimate, 2,900 never-smokers, 4 pCi/L action level, “consider fixing” 2–4 pCi/L) | epa.gov |
| EPA-2 | US EPA, A Citizen’s Guide to Radon (2016 PDF): ~1 in 15 US homes elevated; short-term tests 2–90 days, long-term >90 days; follow-up testing steps | epa.gov |
| EPA-3 | US EPA, Consumer’s Guide to Radon Reduction (2016 PDF): sub-slab suction most common and usually most reliable; up to 99% reduction; post-mitigation test within 30 days and no sooner than 24 h; fans 5+ years, maker warranties rarely over 5 years; retest every 2 years; sealing alone not recommended | epa.gov |
| EPA-4 | US EPA, Home Buyer’s and Seller’s Guide to Radon (PDF) | epa.gov |
| EPA-5 | US EPA, Map of Radon Zones + county data (radon-zones-202406.json) | epa.gov |
| EPA-6 | US EPA, How can you find a qualified radon service provider (NRPP and NRSB are the two privately run national proficiency programs) | epa.gov |
| ANGI | Angi, “How Much Does a Radon Mitigation System Cost? [2026 Data]” (updated Sep 28, 2026; 1,184 projects; $805–$1,326, avg $1,043; cost by method and city) | angi.com |
| HA | HomeAdvisor, “How Much Does a Radon Mitigation System Cost in 2026?” ($786–$1,274, avg $1,028; active suction $1,000–$3,000; passive $500–$2,500; water $1,200–$5,000; permits $25–$150) | homeadvisor.com |
| PA-1 | PA DEP news release, Jan 9, 2025 (systems typically $800–$1,200; kits ~$20–$30) | pa.gov |
| PA-2 | PA DEP, Pennsylvania Consumer’s Guide to Radon Reduction (booklet 2900-BK-DEP1554; $500–$2,000, avg $1,000; replacement fans ~$250–$350) | pa.gov |
| PA-3 | PA DEP Radon Services Directory (certified mitigators list dated Oct 1, 2026) | pa.gov |
| PA-4 | PA DEP radon test results 1986–present, PA Open Data dataset vkjb-sx3k | data.pa.gov |
| PA-5 | PA Real Estate Seller Disclosure Law (Residential Real Estate Transfers Law, PDF from PA Dept of State) | pa.gov |
| PA-6 | 25 Pa. Code § 240.111 (no one may mitigate or advertise mitigation in PA without DEP certification or being an employee of a certified firm; firms need ≥1 certified individual in responsible charge) | pacodeandbulletin.gov |
| MN-1 | Minnesota Dept of Health, Radon Mitigation Systems ($1,500–$3,000; radon system tag placed by licensed professional with installer name, phone, install date, license number) | health.state.mn.us |
| MN-2 | Minnesota Dept of Health, Find a Radon Mitigation Professional (avoid quotes under $1,000; free MDH inspection of systems installed after June 2020) | health.state.mn.us |
| MN-3 | Minn. Stat. § 144.496 (Minnesota Radon Awareness Act, seller disclosure) | revisor.mn.gov |
| MN-5 | MDH Radon Service Providers search (licensed mitigation professionals) | radon.web.health.state.mn.us |
| MN-6 | MDH MN Public Health Data Access, radon testing data 2016–2025 | mndata.web.health.state.mn.us |
| IL-1 | IEMA Guide to Radon Mitigation (PDF; $800–$1,200) | iemaohs.illinois.gov |
| IL-2 | 420 ILCS 46/10, Illinois Radon Awareness Act (seller disclosure + pamphlet) | ilga.gov |
| IL-3 | IEMA Radon Tracking System, active licensee listing (Mitigation Professional) | public.iema.state.il.us |
| IL-4 | Illinois Dept of Public Health radon FAQ ($800–$1,200; IEMA study: 41% of homes tested above 4 pCi/L; Radon Awareness Act + Real Property Disclosure Act require buyer be informed and test results disclosed; no testing or mitigation required) | dph.illinois.gov |
| IA-1 | Iowa HHS radon fact sheet (PDF; $800–$2,500; national average ~$1,200; Iowa average indoor radon >6× national average; Iowa leads the nation in % of homes over 4 and over 20 pCi/L) | hhs.iowa.gov |
| IA-2 | Iowa HHS, Iowa Credentialed Radon Mitigation Specialists (PDF, generated 9/24/2026) | hhs.iowa.gov |
| IA-3 | Iowa Code ch. 136B (136B.1: credential required to perform abatement, exempt for own building or unpaid work; 136B.2: report results to HHS within 30 days; real-estate disclosure under 558A.4(2)) | legis.iowa.gov |
| IA-4 | Iowa Code ch. 558A (real estate disclosures) | legis.iowa.gov |
| OH-1 | Ohio Dept of Health, Radon booklet (May 2024): ~50% of homes tested elevated each year; mitigation contractor must be ODH-licensed; post-install system “can cost $2,000 or more” | odh.ohio.gov |
| OH-2 | Ohio Rev. Code § 3723.02 (license required for radon mitigation) | codes.ohio.gov |
| OH-3 | Ohio Residential Property Disclosure Form (radon question) | dam.assets.ohio.gov |
| OH-4 | Ohio Rev. Code § 5302.30 (property disclosure) | codes.ohio.gov |
| CO-1 | CDPHE Radon FAQ ($1,300–$3,000; ~$500 to activate a passive system; ~$150 professional test) | cdphe.colorado.gov |
| CO-2 | Colorado DORA press release, “Radon professional licensure now required in Colorado” (Aug 16, 2022): licensure required from July 1, 2022; CDPHE data ~50% of CO homes above 4 pCi/L; ~500 radon deaths/yr in CO (EPA) | dora.colorado.gov |
| CO-3 | C.R.S. § 12-165-107 (exemptions: owner-occupied single-family home; supervised assistants; government agents; approved training) | colorado.public.law |
| CO-4 | C.R.S. § 12-165-108 (mitigation licence requires proficiency-program certification in mitigation) | colorado.public.law |
| CO-5 | Colorado DORA Office of Radon Professionals + licence roster download (“RMT – Radon Mitigation Professional”), retrieved 2026-11-02 | dpo.colorado.gov · apps2.colorado.gov |
| WI-1 | Wisconsin DHS, How to Find a Contractor (no state license; recommends NRPP/NRSB) | dhs.wisconsin.gov |
| NRPP | National Radon Proficiency Program pro search | nrpp.info |
| NRSB | National Radon Safety Board find-a-pro | nrsb.org |
| CEN | US Census Bureau, Vintage 2024 county population estimates | www2.census.gov |
RadonCosts provides general information, not medical, legal or engineering advice. Always confirm an installer’s credential with the issuing program before hiring.