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Buying a house with radon
Testing before closing, and when it is a deal breaker.
Read the guideBuying and selling15 min read
Radon disclosure
What sellers share, what buyers ask, and how to find your state's rule.
Short answer
EPA's guide ties radon disclosure to state or local government requirements, and rules vary by state, so start with your state radon program. Whatever the rule, EPA's advice is to share: give buyers your test results and the records of any radon fix.
Next step: see how a radon test fits a home sale. Testing for a home sale
Key takeaways
- EPA's guide for buyers and sellers ties radon disclosure to state or local government requirements. Rules vary by state.
- Five state radon programs publish a home sale disclosure rule on their own pages, checked here in their own words: Illinois, Iowa, Minnesota, New Jersey and Utah.
- Start with your state radon program. Radon411 lists them in state radon programs.
- Whatever your state requires, EPA's advice to sellers is to provide test results to the buyer and keep the records of any fix.
- A seller with a radon system should give buyers information on its operation and maintenance, EPA's Consumer's Guide says.
- A disclosed result is a starting point. A buyer may ask for a new test if it is old, the house changed, or it missed the level the buyer will use.
Radon disclosure: what it is and where the rules come from
Radon disclosure means telling a buyer, or a tenant, what you know about radon in a home: whether it has been tested, what the results were, and whether anything was done about them. Whether and how you must disclose depends on where the home is. EPA's Home Buyer's and Seller's Guide to Radon mentions a state or local government that requires disclosure of radon information to buyers; it leaves the details to them.
- Radon disclosure
- What a seller or landlord tells the other party about radon in a home: test results, when and where the tests were taken, and any radon-reduction work. The rule for what must be disclosed, and how, varies by state.
Radon regulations: who sets which rules
Radon rules touch a home sale in several places, and EPA's guides say which level of government each belongs to. Disclosure is only one of them.
| Area | Detail |
|---|---|
| Disclosure to buyers | EPA's guide refers to a state or local government that requires disclosure of radon information to buyers. |
| Who may test and mitigate | Many states require radon professionals to be licensed, certified or registered. EPA says state programs exercise a statutory authority to oversee radon service providers, for example through licensing. |
| How tests are done | Some states require radon measurement testers to follow a specific testing protocol. |
| Test interference | Disturbing or interfering with a test device or closed-house conditions is illegal in some states. |
| Mitigation systems | A system installed in your home must conform to your state's regulations. Where there are none, EPA recommends its most current voluntary consensus-based standards. |
| New construction | Building codes in your state or local area may require radon-resistant construction features. WHO says the United States is among the places where building codes include such measures. |
| The action level | EPA's state contacts page says the radon action level should comply with the guidance of the country, state or other local jurisdiction where the test is conducted. |
Where to look up radon laws
EPA's state radon contacts page leads to each state's radon contact and links to the Environmental Law Institute's database of radon laws. EPA's buyer and seller guide says to call your state radon office first for state-specific radon measurement or requirements. Radon411's state radon programs page gathers the offices in one list.
The radon disclosure form: what it can cover and what to attach
If your state uses a seller disclosure form with a radon question, the form sets the wording. What EPA's guides add is what a useful answer looks like: not just yes or no, but the evidence behind it.
- Every test report you have, with the result, the dates, where in the home the device sat and who ran it. EPA says the tester's ID number, if available, should be noted in the report.
- Proof the test was done correctly. EPA tells sellers to review a past test against its Radon Testing Checklist before providing it.
- What changed since. Renovations, alterations and changes to heating, ventilation or air conditioning can affect radon levels.
- Any radon-reduction work, with before and after results, the contract, the operating and maintenance instructions and any warranties.
Radon gas disclosure versus a radon test
A radon gas disclosure reports what the seller knows. A test measures the house. They answer different questions, and a disclosure of no known radon is not a result. Testing is the only way to know the radon level in a specific building. EPA also says you cannot predict a home's level from state, local or neighborhood measurements, so a note that the area is low is not a reading either.
State radon disclosure laws that state programs publish
Radon411 read the radon program page of every state on 2026-09-25 and recorded a disclosure rule only where the program states one in its own words. The five below are the ones Radon411 could also check again, word for word, against the program's live page. The table gives each rule as the program words it, and links to the page; nothing here is legal advice, and a rule can change after the date shown.
| State | What the state program says | Applies to |
|---|---|---|
| Illinois | The Illinois Radon Awareness Act requires the seller to provide to the buyer of any interest in residential real property the IEMA-OHS pamphlet "Radon Testing Guidelines for Real Estate Transactions" and the Illinois Disclosure of Information on Radon Hazards | Sales |
| Iowa | Per Iowa Code chapters 543B.9 and 543B.18, a seller must disclose any known tests for the presence of radon and if yes, provide the date of last report and the result(s) | Sales |
| Minnesota | The Minnesota Radon Awareness Act requires specific disclosure and education be provided to potential home buyers during residential real estate transactions | Sales |
| New Jersey | Under the law, the seller must provide the buyer, at the time the contract of sale is entered into, with a copy of the results of the radon test and evidence of any mitigation or treatment | Sales |
| Utah | Sellers disclose "Hazardous Conditions: Are there any hazardous conditions on the Property such as Radon gas in house or well?" | Sales |
Two of the same programs say what is not required. Iowa's says there are currently no rules at the state level requiring testing or mitigation during a real estate transaction, and Minnesota's says radon testing and mitigation are not required during real estate transactions, but testing is highly recommended. Disclosure, in other words, is usually about what the seller knows, not a duty to test. Each state's program, with its contact details, is in state radon programs.
What the state rules ask a seller to hand over
The rules differ in what changes hands. Minnesota's is the most detailed: before signing a purchase agreement to sell or transfer residential real property, the seller shall disclose, in writing to the buyer, any knowledge the seller has of radon concentrations in the dwelling, along with a set list of items. Illinois and Iowa add a state pamphlet or fact sheet; New Jersey requires the test results themselves and evidence of any mitigation.
| State | What the seller provides |
|---|---|
| Minnesota | Whether a radon test or tests have occurred on the property; the most current records and reports pertaining to radon concentrations; a description of any radon concentrations, mitigation, or remediation; information regarding the radon mitigation system, including system description and documentation; a radon warning statement; and a copy of the publication "Radon in Real Estate Transactions" |
| Illinois | The pamphlet "Radon Testing Guidelines for Real Estate Transactions" and the Illinois Disclosure of Information on Radon Hazards; the program says its disclosure form may be used to satisfy the requirements of the Radon Awareness Act |
| Iowa | Any known tests for the presence of radon, with the date of last report and the result(s); the seller must also acknowledge providing the "Iowa Radon Home-Buyers and Sellers Fact Sheet", and the buyer must acknowledge receiving it |
| New Jersey | A copy of the results of the radon test and evidence of any mitigation or treatment, at the time the contract of sale is entered into |
| Utah | An answer to the disclosure form's hazardous conditions question, which names radon gas in the house or well |
Minnesota adds that individuals may create their own disclosure that meets the requirements of the Minnesota Radon Awareness Act, and that buyers and sellers can negotiate radon testing, radon mitigation system installation, and who is responsible for the costs. Ultimately, its page says, it is up to the buyer to decide what is an acceptable level of radon.
What state programs tell real estate professionals
Several programs write directly to agents, and their advice is practical. New Jersey's says radon testing has been integrated within most real estate transactions in the state, and that 75-80% of the approximately 60,000 radon tests done there each year are done as part of real estate sales. It reminds agents of a seller's obligation to reveal to a prospective buyer the results of all radon testing and any mitigation, that only state-certified companies can test for and mitigate radon there (homeowners testing or mitigating their own homes are the exemption), and that even sealing and mailing back the test kit would interfere with the process.
| Program | What it advises |
|---|---|
| Utah | Early disclosure builds an atmosphere of trust and encourages an honest exchange among all parties; problems are much more likely to arise if radon is suspected when the parties are already well into a transaction |
| Utah | Contingencies regarding radon may be included, but they should be specific to acceptable levels of radon, not upon testing itself |
| Utah | Buyers and sellers will have to decide whether it is acceptable for the company that tested for radon to be the same company to mitigate the home |
| Minnesota | A licensed radon professional should conduct testing during real estate transactions when an unbiased third-party is desired |
Utah's page also lists what a buyer should request when a seller discloses radon: the results of the previous tests and the name of the person who performed the test, the same questions EPA's guide puts to buyers. The section below turns them into a checklist.
What a seller should share
EPA's advice to sellers points toward sharing, whatever the local rule. If you have tested and the test was done correctly, EPA says to provide your test results to the buyer. If you fixed a problem, save the test results and all information about the steps taken; EPA says this could be a positive selling point. EPA's Citizen's Guide says to test now and save the results in case the buyer is interested in them.
Disclosing a radon mitigation system
“If you are selling a home that has a radon reduction system, inform potential buyers and supply them with information about your system's operation and maintenance.”
The same guide says the installation contract should declare whether any warranties or guarantees are transferable if you sell your home, and that you should ask the contractor for written operating and maintenance instructions and copies of any warranties. Those are the documents a buyer will ask for. More in selling a house with radon.
Well water results
If the home is on a private well and you tested the water for radon, keep that result with the air results. EPA says that when a home has elevated radon in air and its water comes from a private well, the water should be tested too, and that testing water uses different devices and procedures from testing air. See radon in well water.
What a buyer should ask, and how to judge a disclosed result
EPA tells buyers to ask the seller for their radon test results, and for any information about a radon-reduction system. Before you accept the seller's test, EPA says to find out:
The results
The results of previous testing, from the report itself.
Who tested
The homeowner, a radon professional or some other person. EPA's Citizen's Guide notes buyers frequently want tests made by someone not involved in the sale.
Where the device sat
Especially if you may live in a lower level than the one tested, such as a basement.
What changed since
Structural changes, alterations or changes to the heating, ventilation and air conditioning system.
Whether it met the checklist
If you accept the seller's test, make sure it followed the Radon Testing Checklist.
Read this figure as textHide the text version
- Below 2 pCi/L (below 74 Bq/m³)Below both of EPA's guidance levels.
- 2 to 4 pCi/L (74 Bq/m³ to 148 Bq/m³)EPA recommends considering a fix when the level is between 2 and 4 pCi/L.
- At or above 4 pCi/L (148 Bq/m³ and up)EPA recommends fixing a home when the radon level is 4 pCi/L or higher.
EPA recommends fixing a home when the radon level is 4 or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Read any disclosed number with the radon result interpreter.
When a disclosed result is not enough
EPA says a buyer may ask for a new test if the checklist items were not met, the last test is not recent (EPA's example is within two years), the home was renovated or altered since, or the buyer plans to use a lower level than was tested. A buyer may also ask for a new test if the state or local government requires disclosure of radon information to buyers. If a new test is needed, EPA says to discuss it with the seller as soon as possible.
Radon disclosure for a lease or rental, and for new homes
EPA's Citizen's Guide notes that more and more home buyers and renters are asking about radon levels before they buy or rent a home. Whether a landlord must disclose radon, and how, is a question for the state and locality, and rules vary by state. Some states do have rules for leases; Illinois's real estate page, for one, lists material for lessors and tenants, so ask your state program. Elsewhere, a tenant can still ask the landlord whether the unit has been tested and for the results.
New homes and builders
For a new home, EPA's guides say to ask the owner or builder whether it has radon-resistant features, and building codes in your state or local area may require them. A radon-resistant home is not a tested home: EPA says that even if built radon-resistant, every new home should be tested as soon as possible after occupancy. See radon-resistant new construction and testing a new home.
How to find the radon disclosure rule that applies to you
Find your state radon office
Use Radon411's state radon programs list or EPA's state contacts page. EPA says to call your state radon office first for state-specific requirements.
Ask about disclosure and testing
Ask whether the state or the locality requires radon disclosure in a sale or a lease, and whether it requires testers to follow a specific protocol.
Read the forms for the transaction
Your agent or attorney can show you the disclosure form, if any, used where the home is.
Gather your records
Test reports, mitigation contracts, before and after results, operating instructions and warranties.
Put what you share in writing
Give the buyer copies, and note in the contract how results are shared.
A state radon program can also point you to credentialed testers and mitigators; Radon411 keeps a directory of radon professionals.
Radon disclosure: questions
Do sellers have to disclose radon test results?
In some states, yes. New Jersey's program says the seller must provide the buyer a copy of the radon test results and evidence of any mitigation; Iowa's says a seller must disclose any known tests with the date and results. Rules vary by state; EPA advises sharing results whatever the rule. Check your state's radon program.
Is radon testing required to sell a home?
Not in the states whose programs address it. Iowa's program says there are no state rules requiring testing or mitigation during a real estate transaction, and Minnesota's says testing is not required but highly recommended. EPA recommends testing before you list. Whether your town or your buyer's contract requires one varies, so ask your state radon office.
Why are radon tests sometimes required before the sale of a house?
A requirement can come from a state or local rule, or from the purchase contract. EPA's guide suggests the contract specify where the test will be located, who conducts it, what type it is and when it is done.
Can a radon disclosure be waived?
Any waiver is a question of state law and of your contract. Ask your state radon program and a real estate attorney where the home is.
Do you have to disclose if you remediate radon?
The legal answer depends on your state. EPA's Consumer's Guide says that if you are selling a home with a radon reduction system, inform potential buyers and supply information about its operation and maintenance.
Is there a radon tenant disclosure rule?
Rules for rentals vary by state, and some states have them; Illinois's radon program, for example, publishes material for lessors and tenants. Ask your state radon program what applies to a lease where the home is.
My disclosure said no radon, but my test came back high. What now?
A disclosure of no known radon is not a test result, and levels can change. Confirm the result, fix the home if it is high, and ask your state radon program about any rules for your situation. See high radon levels.
If a buyer's test finds radon, does the seller have to tell the next buyer?
That is a state question, and rules vary by state. EPA's advice to sellers is to provide test results to buyers and to fix a high level before placing the home on the market.
Which states require radon disclosure?
Five state radon programs publish a home sale disclosure rule on their own pages: Illinois, Iowa, Minnesota, New Jersey and Utah. Other states' rules can sit in real estate law or cover leases; ask your state radon office.
What does the Minnesota Radon Awareness Act require?
Before a purchase agreement is signed, the seller discloses in writing what they know about radon in the home: tests, current records, any mitigation, system documentation, a radon warning statement and the state's "Radon in Real Estate Transactions" publication, its health department says.
What does the Illinois Radon Awareness Act require?
The state program says the seller must give the buyer the pamphlet "Radon Testing Guidelines for Real Estate Transactions" and the Illinois Disclosure of Information on Radon Hazards.
Does Iowa require a radon test to sell a house?
No. Iowa's radon program says there are currently no rules at the state level requiring testing or mitigation during a real estate transaction. A seller must disclose any known tests, with the date of the last report and the results, and give the buyer the state's fact sheet.
Does New Jersey require radon testing in a home sale?
Its program describes a disclosure duty, not a testing mandate: the seller must give the buyer a copy of the radon test results and evidence of any mitigation. It also says 75-80% of the state's radon tests are done as part of real estate sales, and only state-certified companies may test for others.
Can a radon contingency just say the buyer may test?
Utah's program advises that radon contingencies should be specific to acceptable levels of radon, not upon testing itself. EPA's guide lists what the contract can specify, from the test location to who pays for any mitigation.
Can a real estate agent pick up or mail the test kit?
New Jersey's program warns that even sealing and mailing back the test kit would interfere with the process. Leave the device to the tester and keep closed-house conditions.
Where do I find my state's radon disclosure rule?
Start with your state radon office, listed in state radon programs. EPA's state contacts page also links to the Environmental Law Institute's database of radon laws.
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