Chapter 04 — The Colorado file

Radon testing & mitigation in Colorado

Current CO DORA credentials from the official Colorado roster. We group people by the city on that file. We do not invent neighborhoods. Source: CO DORA.

Latest credential check September 11, 2026. Methodology Individual record dates may be earlier.

766current listings
538testing
228mitigation
Fig. 4 — 700 of 766 current listings are mapped. 65 records have no mappable in-state place. 1 record has an in-state place but no verified city or county coordinate. Each pin is a current listing at the Census city or county centroid on the file, approximate. Pins that share a place are spread so you can click them. Not street addresses.

§ 4.1

Cities with listings

A city appears only when at least one current listing serves it.

§ 4.3

How to verify a radon credential in Colorado

CO DORA licenses radon work in Colorado and publishes a list we import monthly. Match the name and credential number on the official page before you hire.

Official CO DORA verification page · All fifty states · reviewed September 8, 2026

§ 4.4

Questions about radon credentials in Colorado

Does Colorado license radon testers and mitigators?

CO DORA licenses radon work in Colorado and publishes a current list with credential numbers. This site imports that list and re-checks it monthly. 766 current Colorado listings appear here as of September 11, 2026.

How do I verify a radon credential in Colorado?

Open the CO DORA lookup at https://apps2.colorado.gov/dora/licensing/Lookup/LicenseLookup.aspx, search the name, and match the credential number digit for digit. Status can change between our monthly check on September 11, 2026 and the day you hire. If the official page disagrees with this directory, the official page is right.

Is an NRPP or NRSB certification enough in Colorado?

Colorado issues its own radon credential through CO DORA, so a national NRPP or NRSB certification is not a substitute for it. Every Colorado listing on this site shows the CO DORA number, not a national one.