Public directory

Find a certified radon tester or mitigator

An independent index of people who appear on official certification and license lists for Iowa, Pennsylvania, Ohio, Minnesota, North Dakota, Colorado, Illinois, New York, Kansas, Nebraska, Indiana, Montana, South Dakota, Wisconsin, Missouri, Connecticut, Massachusetts, Kentucky, Rhode Island, Tennessee, West Virginia, Delaware, Virginia, Florida, Maine, New Jersey, Maryland, Utah, California, Oregon, Nevada, Washington, Idaho, New Hampshire, Michigan, and Wyoming. Names are transcribed from those sources. No invented testers. No paid placement.

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How to use the lists

• State certification or licensure is what lets someone test or mitigate for others in that state. National NRPP/NRSB credentials are not a substitute where a state license is required.
• People who appear on both a tester list and a mitigator list are marked measurement and mitigation.
• City is the address of record on the source list. Some licensees are based in a neighboring state.
• Ohio official list is map-only. This index ships the 8 names that could be verified from NRPP and points you to NRPP, NRSB, and ODH for everyone else.
• South Dakota does not issue a state radon license and publishes no public roster. The South Dakota page links DANR plus NRPP/NRSB only — no invented names.
• Wisconsin does not require state radon licensing and publishes no public roster. The Wisconsin page links DHS plus NRPP/NRSB only — no invented names.
• Missouri DHSS publishes no public radon contractor roster. The Missouri page links DHSS plus NRPP/NRSB only — no invented names.
• Connecticut does not issue a state radon license. The Connecticut page is the complete CT DPH public lists of nationally certified measurement and mitigation professionals (PDFs dated 3-31-2025; retrieved 2026-09-07) — no invented names.
• Massachusetts does not issue a state radon license. The Massachusetts page is the complete MA DPH public lists of nationally certified measurement and mitigation professionals (PDFs updated 07/08/2026; retrieved 2026-09-08) — no invented names.
• Kentucky Board of Radon Safety publishes no downloadable measurement/mitigation roster. The Kentucky page links the board plus NRPP/NRSB only — no invented names.
• Rhode Island requires RIDOH licenses for testing businesses and mitigation contractors. The Rhode Island page is the complete RIDOH public lists (retrieved 2026-09-11) — no invented names.
• Tennessee does not license radon testers or mitigators and publishes no public roster. The Tennessee page links TDEC plus NRPP/NRSB only — no invented names.
• West Virginia licenses radon testers, mitigation specialists, contractors, and labs through OEHS RTIA. The West Virginia page is the complete public license search (retrieved 2026-09-13) — no invented names.
• Delaware does not certify radon contractors. The Delaware page is the official DHSS voluntary list of radon service companies (PDF Rev.7/19; retrieved 2026-09-14) — no invented names.
• Virginia Board for Contractors issues an RMC (radon mitigation) specialty on Class A/B/C licenses. The Virginia page is the complete RMC filter of the official DPOR regulant lists (updated 2026-09-14; retrieved 2026-09-15). VDH also requires NRPP/NRSB for professional testers and mitigators — no invented names.
• Florida requires DOH certification for radon mitigation and measurement businesses. The Florida page is the complete DOH certified mitigation-business PDF (dated 31-Aug-26; retrieved 2026-09-16). Measurement businesses remain on the separate DOH PDF linked from that page — no invented names.
• Maine registers radon service providers through the Radiation Control Program ALMS registry. The Maine page is the complete unique set of active companies with Test Air, Portable Lab (air), and/or Mitigate Air from official ALMS CSV exports (retrieved 2026-09-17). Air only — no invented names.
• New Jersey requires DEP certification for radon measurement and mitigation businesses and professionals (N.J.A.C. 7:28-27), but NJDEP does not publish a current downloadable public certified-business roster. The New Jersey page links DEP verification plus official sources only — no invented names.
• Maryland MDE and MDH do not publish a current downloadable public statewide roster of certified radon measurement or mitigation businesses; both point homeowners to NRPP and NRSB. The Maryland page links MDE/MDH plus NRPP/NRSB only — no invented names.
• Utah requires a DOPL contractor license for radon mitigation and NRPP certification for mitigation professionals. The Utah page is the DOPL Construction Business Registry Active opted-in S354 Radon Mitigation search (20 firms; retrieved 2026-09-20) — incomplete vs all licensees; re-check DOPL license lookup and NRPP/NRSB — no invented names.
• California requires CDPH listing for radon measurement and mitigation providers (NRPP or NRSB plus CDPH submission). The California page is the complete CDPH Certified Radon Services Providers tester and mitigator tables (231 tester rows · 12 mitigators; retrieved 2026-09-24) — no invented names. Re-check CDPH and CSLB before hiring.
• Oregon Health Authority publishes public lists of radon measurement and mitigation companies in Oregon with at least one NRPP- or NRSB-certified technician on staff. The Oregon page is the complete OHA certified measurement and mitigation company tables (36 measurement · 12 mitigation; retrieved 2026-09-25) — no invented names. Re-check OHA and NRPP/NRSB before hiring.
• Nevada does not appear to issue a separate state radon license roster. The EPA-funded Nevada Radon Education Program at University of Nevada, Reno Extension compiles certified measurement and mitigation professionals from NRPP/NRSB (and lists NV Contractors License # when provided for mitigators). The Nevada page is the complete NREP certified tester and mitigation contractor tables (25 measurement · 7 mitigation; retrieved 2026-09-26) — no invented names. Re-check NRPP/NRSB and the Nevada State Contractors Board before hiring.
• Washington DOH publishes no public statewide roster of radon measurement or mitigation businesses and does not offer a state radon license lookup on its site. The Washington page links DOH plus NRPP/NRSB (and L&I hiring guidance) only — no invented names.
• Idaho DHW publishes no public statewide roster of radon measurement or mitigation businesses and does not offer a state radon license roster on its site. The Idaho page links DHW plus NRPP/NRSB only — no invented names. DHW notes that 2 out of 5 Idaho homes have elevated radon (retrieved 2026-10-02).
• New Hampshire DHHS publishes no public statewide roster of radon measurement or mitigation businesses. OPLC requires current NRPP or NRSB certification for airborne radon mitigation installers (RSA 310-A:189-a). Measurement pros are not state-certified, but DHHS recommends nationally certified measurement professionals (especially for real estate). The New Hampshire page is an honest explainer linking DHHS, OPLC, NRPP, and NRSB only — no invented names. DHHS materials note about 1 in 3 NH homes have elevated radon; air only (retrieved 2026-10-03).
• Michigan does not license or regulate radon measurement or mitigation contractors, and EGLE publishes no public statewide company roster (it says it can supply lists of NRPP/NRSB-certified providers on request). The Michigan page is an honest explainer linking EGLE, NRPP, and NRSB only — no invented names. EGLE says about 1 in 4 Michigan homes exceed the federal action level and elevated radon has been found in all 83 counties; air only (retrieved 2026-10-05).
• Wyoming WDH publishes no public statewide roster of radon measurement or mitigation businesses; its Find a Professional page points to NRPP/NRSB. The Wyoming page is an honest explainer linking WDH, NRPP, and NRSB only — no invented names. Wyoming's radon fact sheet says a majority of the state is EPA Zone 1, and WDH offers free test kits while supplies last; air only (retrieved 2026-10-12).
• Montana does not issue a state radon license. The Montana page is the complete set of unique businesses from the DEQ Radon Service Providers GIS (retrieved 2026-09-03), marked mitigation because DEQ titles the map as mitigation service providers. Always re-check NRPP/NRSB and the DEQ map before hiring.
• New York does not issue a state radon license. The New York page is the complete NYS DOH public list of nationally certified testers and mitigators (revised May 2026).
• Kansas is the complete KDHE certified measurement and mitigation technician list (dated 2026-07-14). City is the business address of record; some certified people are based outside Kansas.
• Nebraska is the complete DHHS licensed measurement and mitigation business lists (measurement PDF dated 2026-07-28; mitigation PDF dated 2026-05-21; retrieved 2026-09-01). These are licensed businesses, not individual technicians.
• Indiana is the complete IPLA public Active Radon license search (Primary/Secondary Testers and Mitigators; retrieved 2026-09-02). City is the address of record; some licensed people are based outside Indiana. Always re-check status in the IPLA search before hiring.