# Certified radon testers & mitigators

> US directory of people with a current radon testing or mitigation credential on an official state file, or a current NRPP or NRSB certification where the state has no public roster on this site. Every listing shows a credential number, issuing body, last-verified date, and a link to that source.

This site is a roster, not a contractor. It does not test homes, install systems, match people to sales, publish star ratings, or display EPA-certified badges. EPA does not certify radon contractors. A national certification is not a state license. Maps pin Census city or county centroids and are labeled approximate; official files almost never include a street, and this site does not invent one.

## What this directory is

- Current credentials only. Expired or unknown status is not listed.
- US English. Services are testing, mitigation, and optional new-construction.
- City pages use the city printed on the official record. ZIP-radius search is not turned into a city graph.
- `/find` is a ZIP resolver and is not indexed.

## Key pages

- [Home](https://radontestingcompanies.com/): Search by ZIP or browse states
- [About](https://radontestingcompanies.com/about): What this directory is and is not
- [Methodology](https://radontestingcompanies.com/methodology): Sources, NRPP/NRSB rules, geography we do not invent
- [Contact](https://radontestingcompanies.com/contact): No office, no street address
- [Pennsylvania](https://radontestingcompanies.com/pennsylvania): Example state hub with a .gov roster
- [Allegheny County testing](https://radontestingcompanies.com/pennsylvania/allegheny/testing): Example city/county roster

## Optional

- [Claim or update a listing](https://radontestingcompanies.com/claim): Correct a listing that already appears on an official file. Cannot add someone missing from that file.