Chapter 01
Certified radon testers & mitigators
Current credentials for radon testing and mitigation in the United States. Each listing shows a credential number, the issuing body, the date we last checked the official file, and a link to that file. This is a directory, not a contractor. EPA does not certify radon contractors.
Opens a city or county we already publish.
Or open a place from a file we import:
4,780current listings
50states with listings
1,224cities and counties
August 29, 2026last verified. Methodology
Chapter 02
Cities and counties with the most listings
- Allegheny County, PA 84
- Denver, CO 77
- Mitchell County, KS 74
- Colorado Springs, CO 72
- Montgomery County, PA 60
- Johnson County, KS 42
- Sedgwick County, KS 41
- Westmont, IL 41
- Littleton, CO 40
- Centennial, CO 39
- Minneapolis, MN 36
- Indianapolis, IN 35
Chapter 03
States with current listings
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- District of Columbia
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming