A radon disclosure form is the document a home seller uses to tell a buyer, in writing, what they know about radon gas in the property before the purchase agreement is signed. Roughly 37 states require some version of this disclosure in residential sales, though the format, timing rules, and required attachments vary by jurisdiction.1Policy Surveillance Portal. State Radon Laws There is no federal law requiring radon disclosure in private home sales; the Indoor Radon Abatement Act sets a national indoor-air goal and funds state radon programs, but leaves transaction-level disclosure rules to the states.2Office of the Law Revision Counsel. 15 USC Chapter 53, Subchapter III – Indoor Radon Abatement The EPA recommends action when indoor concentrations reach or exceed 4 picocuries per liter (pCi/L), and that threshold drives most of the questions on the form.3Centers for Disease Control and Prevention. Reducing Radon Levels in Your Home
Where to Get the Correct Form
Your state’s real estate commission, department of health, or environmental agency typically publishes the approved form. Some states embed the disclosure directly into their standard residential purchase contract; others issue it as a standalone document. If your state does not provide a template, real estate agents often use a form developed by their local association of Realtors. The EPA also publishes the “Home Buyer’s and Seller’s Guide to Radon” (EPA 402/K-24/001), which several states require sellers to hand to buyers alongside the disclosure itself.4U.S. Environmental Protection Agency. Radon and Real Estate Resources
Check with your state radon office or real estate commission for the current version. Using an outdated or unofficial form can create problems at closing, and a form that omits a state-required warning statement may not satisfy the statute at all.
Completing the Seller’s Knowledge Section
The seller’s portion of the form asks what you know, not what you’ve guessed. Most forms use a short series of yes/no/unknown checkboxes followed by blanks for supporting detail. Expect questions covering:
- Whether radon testing has ever been performed on the property. If a test was done during your ownership, or if a prior owner’s results were included in your closing documents, check yes and attach what you have.
- The most recent test results, including the concentration in pCi/L, the date, and the name of the company or professional who performed the test. Note if you used a home test kit.
- Whether known concentrations are at or above the EPA action level of 4 pCi/L.5HUD Exchange. Summary of Radon Standards of Practice
- Whether a radon mitigation system is installed. If yes, the form will ask for a description and documentation.
- Whether mitigation reduced levels below 4 pCi/L. Attach post-mitigation test results if you have them.
If you genuinely do not know the answer, mark it “unknown.” A blank field is not the same as an “unknown” checkbox. Blanks can look like oversights, and in a later dispute they may work against you.
The form is a declaration of your actual knowledge. It is not a guarantee that the home is radon-free, and completing it honestly does not obligate you to test before selling. But false answers or concealment of known results expose you to civil liability for misrepresentation, and in states with dedicated radon disclosure statutes, failing to complete the form at all can delay or jeopardize the sale.
Documenting a Mitigation System
If the property has an active radon mitigation system, the form asks for more than a yes. Attach whatever records you have: the installer’s name and license number, the installation date, and post-installation test results showing that radon levels dropped below 4 pCi/L. A standard active soil depressurization system, the most common residential setup, includes a PVC vent pipe running from beneath the foundation slab to above the roofline, an electric fan mounted outside the living space, a manometer or pressure gauge indicating whether the fan is running, and sealed cracks and joints in the slab and foundation walls. If the system uses a sump pit as a suction point, note whether the pit cover is sealed.
Buyers and their inspectors will verify these details, so front-loading documentation reduces follow-up requests during the inspection period. If a system predates your ownership and you have no records, say so directly on the form. Wording like “system was present at time of purchase; no installer records available” is far better than a blank section.
The State Warning Statement and Pamphlet
Many of the roughly 37 states that require radon disclosure also require a specific radon warning statement to appear in or alongside the purchase contract. These statements follow a common pattern: they warn the buyer that the property may expose occupants to dangerous levels of indoor radon, note that radon is a Class A human carcinogen and the leading cause of lung cancer among nonsmokers, and state that the seller must share any known test results. Some states write this language into the statute word for word, and paraphrasing is not an option.
Several states also require the seller to hand the buyer an educational pamphlet published by the state health department or the EPA. The pamphlet covers health risks, testing, and mitigation. Skipping it may seem minor, but where the pamphlet is a statutory requirement, the omission can give the buyer grounds to challenge the transaction or seek damages after closing. Ask your agent to confirm which pamphlet your state requires before you sign the purchase agreement.
Timing, Signatures, and Recordkeeping
The completed disclosure must reach the buyer before or at the time the purchase agreement is signed, not after.6Illinois General Assembly. Illinois Code 420 ILCS 46 – Illinois Radon Awareness Act The point is to let the buyer make an informed offer. Handing the form over at closing, when the buyer is already committed, defeats the purpose and may violate the state’s timing rules.
Both parties sign. The seller’s signature certifies that the information is accurate to the best of their knowledge. The buyer’s signature acknowledges receipt of the disclosure and any required pamphlet; it does not mean the buyer accepts the radon conditions or waives the right to test independently. Once signed, keep a copy in your permanent closing file. If a dispute arises years later about what the buyer knew and when they knew it, that signed form is your primary defense.
When the Form Also Applies to Rentals
No federal law requires landlords to disclose radon levels to tenants, but a growing number of states extend their radon disclosure statutes to residential leases, typically for units below the third story. In those states, landlords generally must provide tenants with the warning statement, copies of any test results on file, and the state-published brochure. The obligations mirror a seller’s, and in some jurisdictions failing to provide the disclosure can breach the warranty of habitability and let the tenant cancel the lease. If you are selling rather than leasing, the residential sales form is the one you need; if you also rent property, check whether your state’s statute covers landlords separately.
What Happens If the Form Is Wrong or Missing
Two failure modes cause most trouble. The first is answering falsely or concealing a known test result, which exposes the seller to civil liability for misrepresentation after closing. The second is procedural: using an outdated form, skipping the required warning statement, forgetting the pamphlet, or delivering the disclosure after signing. Procedural mistakes may not surface as damages, but they can delay closing, give the buyer grounds to back out, or in some states create statutory penalties. Both failure modes are avoidable with the current state-approved form, honest answers, attached documentation for any test or mitigation system, and delivery before the purchase agreement is signed.