How to test your Tennessee home for radon
Testing is the only way to know your home's radon level, and it's simple. Tennessee residents can get a short-term test kit free from the state, set it on the lowest lived-in floor for 3 to 5 days, and mail it to the lab. If the result is 4 pCi/L or higher, a second test confirms it before you decide on a fix.
Key facts
How do I get a free radon test kit in Tennessee?
Order one through the Tennessee Radon Program's online form, call the program's hotline at 1-800-232-1139, or email TDEC.Radon@tn.gov. The kit is a do-it-yourself short-term test, and the return postage to the lab is prepaid. See our free test kit page for details.
If you'd rather buy a kit, National Radon Program Services at Kansas State University sells a short-term kit for $20 and a long-term kit for $30, including lab analysis (sosradon.org). Kits are also sold at hardware stores.
Should I use a short-term or long-term test?
Start with a short-term test for a quick answer, then use a long-term test if you want the clearest picture of your exposure.
| Short-term test | Long-term test | |
|---|---|---|
| How long it runs | 2 to 90 days (the free Tennessee kit runs 3 to 5 days) | More than 90 days |
| What it tells you | A snapshot; radon levels rise and fall day to day | Your home's typical, year-round level |
| Best for | A first check, home sales, checking a new system | Deciding about borderline results; ongoing peace of mind |
Should I test myself or hire a professional?
Either works for most homeowners. A do-it-yourself kit is inexpensive and accurate when used correctly. CDC notes that EPA recommends hiring a qualified tester when you're buying or selling a home (CDC). To find one, use the NRPP or NRSB directories. Tennessee doesn't license radon testers, so national certification is the best way to check qualifications. See finding a certified professional.
How do I set up a radon test correctly?
- Close up the house. Keep windows and outside doors closed for at least 12 hours before a short-term test and during it, except for normal coming and going (American Lung Association).
- Pick the right room. Use the lowest level of the home that's regularly lived in. Avoid kitchens, bathrooms, laundry rooms, and crawlspaces.
- Place it carefully. Set the test about three feet off the floor, in the middle of the room, away from drafts, doors, windows, and heat sources (CDC).
- Run it for the full time. For the free Tennessee kit, that's 3 to 5 days only. Write down the start and end times.
- Mail it right away. Send the kit back as soon as the test ends. A late return is one of the most common mistakes the state's lab sees (TDEC).
Step-by-step version: how to run a radon test.
What does my radon result mean?
Use these rules from CDC, or enter your number in our result interpreter.
| Your result | What to do |
|---|---|
| Below 2 pCi/L | No action needed. Retest if you start using a lower floor of the home. |
| 2 to 4 pCi/L | Consider fixing your home. EPA recommends considering mitigation in this range. |
| 4 pCi/L or higher, first short-term test | Run a second test to confirm. |
| 4 pCi/L or higher, average of two short-term tests, or any long-term test | Fix your home. Contact a certified mitigation professional. |
More detail: what your radon result means.
When should I test again?
Retest:
- a few months after a radon reduction system is installed, and every two years after that (American Lung Association)
- after major renovations or structural work
- before turning a basement or lower floor into a bedroom, office, or other living space
- when buying or selling a home, or if the home has never been tested (CDC)
Frequently asked questions
When is the best time of year to test in Tennessee? You can test any time. Radon levels in a home change from day to day and even hour to hour (WHO), which is why a high short-term result should be confirmed with a second test or followed by a long-term test.
Do I need to test every room? No. For a standard home check, test the lowest level that's regularly lived in, as described above.
Who can I call with questions? The Tennessee Radon Program at 1-800-232-1139, or the National Radon Helpline at 1-800-557-2366.
Next step: Order your free Tennessee radon test kit →
Sources: Tennessee Radon Program (TDEC) · CDC – Testing for Radon · American Lung Association – Radon · National Radon Program Services – Test Kits · WHO – Radon fact sheet · NRPP · NRSB
Last reviewed October 17, 2026 by the Tennessee Radon Authority editorial team. How we research.