How Often Should I Test for Radon?
Test your home for radon every 2 years, and test again after major renovations, a radon mitigation system is installed or changed, or you move into a different home. Follow local guidance and any system instructions.
On this page (7 sections)
Test your home for radon every 2 years, then test again after major renovations, mitigation work, or a move to another home. Radon levels can change over time, so a past low result doesn't guarantee that levels remain low.
The right schedule also depends on your location, the test method, and whether you have a radon reduction system. Check local public health guidance and follow any instructions from the professional who installed your system.
How often should you test for radon?
Plan to test every 2 years as a practical routine, unless local guidance or your mitigation system calls for more frequent checks. Test sooner if something changes that could affect radon entry or airflow.
Radon is an odorless gas, so you can't use smell or appearance to tell whether the level has changed. A test is the way to measure it.
If you haven't tested before, start with a home screening. Our guide to How to Test for Radon: The Simple Answer explains the basic process.
What changes mean you should test again?
Test again after a major renovation, a change to a mitigation system, or a move into a new home. These events can alter how air moves or how radon enters the building.
Consider retesting after work that changes a basement, crawl space, foundation, or ventilation. A new addition or a previously unfinished lower level may also change which areas are occupied and where a test should be placed.
After basement work, use the advice on how to test basement for radon to choose a suitable test location. If you change rooms or begin using a lower level more often, review where should a radon test be placed before setting out a kit.
A move is a good reason to test again, even if the home had a previous low result. The earlier measurement reflects conditions at that time and in that home.
Should you retest after radon mitigation?
Yes. Test after a mitigation system is installed or changed to check the radon level under the new conditions.
Keep following the installer’s monitoring advice afterward.
A working system can reduce radon, but a test result is what tells you the measured level in the home. Retest if the system stops running, is repaired or changed, or you notice a new issue that could affect its operation.
Store the test result with the system’s installation and service records. That gives you a comparison point for future checks.
Does the type of radon test change the schedule?
The schedule can stay the same, but the test duration affects what the result represents. A short-term test measures over a brief period, while a long-term test covers a longer span and better reflects average conditions.
A short-term screening can help you decide whether you need follow-up testing. Read what a long-term radon test measures if you want a broader view of levels over time.
For a first measurement, a mail-in kit may be one option. The First Alert Radon Gas Test Kit includes test materials and lab fees, with New Jersey state fees excluded; results are emailed within 72 hours of lab receipt.
The PRO-LAB Radon Test Kit for Home is a short-term option with a 48-hour collection period and lab analysis included.
The Leaping Lynx Radon Test Kit for Home uses a 48-hour short-term test and includes lab analysis; return postage is required.
Follow each kit’s instructions for placement, exposure time, and sample return. For help choosing and setting up a test, see How to Test for Radon at Home: A Quick Guide.
How should you respond to a high result?
Use the result and the test instructions to decide whether to repeat the measurement or seek help. Local public health guidance can explain the action level and next step for your area.
A short-term result gives a snapshot during the test period. If it is raised, a follow-up test may help confirm the level; if you already have a long-term result, use local guidance to understand what it means for your home.
Don't delay getting professional advice if the result is high or you have a mitigation system that may not be working. Keep the test report so you can share the method, date, and result.
How can you make repeat tests comparable?
Use a similar location and follow the same placement instructions each time, unless the area’s use has changed or the instructions call for another spot. Consistent placement makes it easier to compare measurements.
Place the test in a regularly used room on the lowest level where people spend time, following the test kit’s directions. Keep it away from drafts, high humidity, direct sun, and areas where it might be disturbed if the instructions advise this.
Record the date, room, floor, test duration, and result. A radon sampling plan can help you track locations and repeat tests over time.
What is a sensible radon testing routine?
For most households, test every 2 years and retest after major changes to the home or mitigation system. Start with a screening if you haven't tested, then use the result and local guidance to decide whether follow-up is needed.
Choose a short-term kit for a brief screening, or consider a long-term test when you want a broader measure of average conditions. Keep the results and dates together so the next check has a useful point of comparison.
Frequently asked questions
How often should I test for radon in my home?
A common schedule is to test every 2 years, and sooner after major renovations, changes to a mitigation system, or a move to a new home. Radon levels can vary, so follow local public health guidance and the instructions for any installed system.
Should I test for radon after installing a mitigation system?
Yes. Test after the system is installed to check the result, then follow the system professional's advice about ongoing checks.
Retest if the system is changed, stops working, or the home is renovated in a way that could affect airflow or entry paths.
When should I retest for radon after a high result?
Use the result and test type to choose the next step. A short-term result at or above your area's action level may call for a follow-up test or mitigation, while a long-term test gives a better picture of average exposure.
Follow local health guidance.
Does a home need another radon test after renovations?
Test again after major work that changes the foundation, lower-level use, ventilation, or openings near the soil. Renovation can change how radon enters or moves through a home, so compare the new result with the earlier measurement and seek local guidance if it's raised.
