Selling a House With a Radon Problem

Educational only. This explains how these situations generally work. It is not legal, tax or financial advice, and the rules differ by state — talk to an attorney or CPA about your own situation before you act on any of it.

Selling a house with a radon problem: the short answer

Yes, you can sell a house with a known radon problem. There's no federal radon disclosure law, but several states — including Florida, Ohio, Michigan and New York — require disclosing known test results, and most buyers' lenders will want it fixed or credited before closing. A sub-slab mitigation system typically costs $800–$2,500 and brings levels below the EPA's action level in about a day.

This is general educational information, not legal advice. Radon disclosure requirements vary by state — confirm what applies to your sale with a real estate attorney or your state's standard disclosure form before relying on anything here.

What radon actually is, and why it matters for a sale

Radon is a colorless, odorless radioactive gas that seeps up from soil and rock into a home's lowest level. The EPA calls it the number one cause of lung cancer among people who have never smoked, and attributes roughly 21,000 lung cancer deaths a year to it nationally, about 2,900 of them in never-smokers — a figure that traces back to a 2005 U.S. Surgeon General national health advisory and remains EPA's current published estimate (EPA: Health Risk of Radon).

The EPA's action level is 4 picocuries per liter (pCi/L) — the threshold at which it recommends fixing the home — and it recommends considering a fix even between 2 and 4 pCi/L (EPA: What is EPA's Action Level for Radon).

The American Lung Association's January 2025 Radon Action Month release puts it plainly: radon causes about 21,000 deaths a year and is “the number one cause of lung cancer in people who have never smoked” (American Lung Association, January 6, 2025).

Testing: what it costs and when it happens

• DIY short-term kit (2–7 days): roughly $10–$25
• DIY long-term kit (90+ days): roughly $25–$60
• Professional short-term test: roughly $150–$300
• Professional long-term test: roughly $200–$400

A radon test isn't automatically part of a standard home inspection — it's an add-on a buyer requests. During a sale, it's standard practice for a buyer to order a radon test during their inspection contingency window, typically 7–15 days after the contract is signed. If you've tested the house yourself and know the result, most state disclosure laws require you to share it once asked. If you've never tested, you generally have nothing yet to disclose — but a buyer's own test during inspection will often surface it anyway, which is why many sellers test before listing rather than finding out mid-contract.

Mitigation: how it works and what it costs

The standard fix is a sub-slab depressurization (SSD) system — a fan and pipe run from under the slab to above the roofline that draws soil gas out before it enters the living space. It reliably cuts indoor radon by 80–99%, enough to bring most homes below the 4 pCi/L action level. EPA's own cost estimate averages about $1,200, with a typical range of $800–$2,500 depending on house size and foundation type, and most installs take about a day.

Disclosure law varies by state — there's no federal radon disclosure law

Unlike lead-based paint, there's no federal law requiring radon disclosure in a home sale. States handle it individually. Four concrete examples, all in states Restar Acquisitions buys in:

• Florida — Fla. Stat. §404.056(5) requires a specific radon notice in every real estate sale and rental contract statewide.
• Ohio — ORC §5302.30 makes radon gas a required line item on the state's Residential Property Disclosure Form; there's no duty to test, only to disclose what you already know.
• Michigan — MCL 565.957's Seller Disclosure Statement explicitly asks sellers about known radon gas, alongside asbestos and formaldehyde.
• New York — RPL §462's Property Condition Disclosure Statement requires sellers to state whether radon testing was ever performed and, if so, to deliver the test report.

Georgia, North Carolina, Arizona, Missouri, Indiana, Maryland and Alabama don't have a radon-specific statute found in this research; talk to a local real estate attorney or check your state's standard disclosure form for what applies where you are.

Does radon affect financing?

Generally no, for single-family purchases. FHA doesn't require radon testing on single-family loans (HUD's multifamily program does, separately). VA stopped requiring radon testing or certification on appraisals ordered on or after May 1, 2026. Two states outside Restar's footprint — New Jersey and Illinois — have state-level rules requiring radon disclosure or testing specifically tied to real estate transactions; none of Restar's 12 operating states currently have that.

Geography: some of our markets run hotter than others

The EPA maintains Radon Zone designations by county (Zone 1 is highest potential, Zone 3 is lowest), most recently updated September 2026. Based on EPA's own zone maps, Ohio, Indiana and Missouri lean toward higher-potential zones; Florida and Texas lean toward lower-potential zones; Maryland is mixed. Check your specific county on EPA's official state radon maps rather than assuming based on the state alone.

The honest math: fix it first, or sell as-is

Take a house worth $235,000 with a confirmed test result of 6.2 pCi/L, above the action level.

Unlike most hazard guides on this site, radon is a case where fixing it first is usually the clearly better financial move if you have the time: a mitigation system is cheap — well under 1% of most home values — and takes about a day, so the gap between the two paths above is mostly the cost of convenience and speed, not the cost of the hazard itself. The case for a cash sale here is about not wanting to schedule a contractor, wait out a test period, or risk a buyer's lender stalling the deal mid-contract — not about the dollars.

Alternatives to consider

• Test before you list, so you know what you're dealing with instead of finding out mid-contract.
• If elevated, get 2–3 mitigation contractor quotes — it's typically a one-day job.
• Disclose honestly per your state's form, whether or not you've remediated.
• If you don't have $800–$2,500 or a week to spare, a cash sale lets the buyer handle it.
• Talk to a real estate attorney about your state's specific disclosure requirements if you're unsure.

What this means for your decision

Radon is common, well-documented and genuinely fixable — it's rarely a reason a sale falls apart on its own. If you have the time and a few hundred to a couple thousand dollars, mitigating before you list is usually the better math. If you don't, a cash sale lets the buyer handle it while you move on your own timeline. Send us the address and we'll give you a straight comparison for your specific situation.

Common questions

Do I have to test my house for radon before selling?

No. There's no federal or, in most states, state requirement to test before selling. But a buyer will often test during their own inspection period, so many sellers test ahead of time to avoid surprises mid-contract.

Do I have to disclose a radon problem if I know about it?

In states with radon-specific disclosure requirements — Florida, Ohio, Michigan and New York are confirmed examples — yes, known results generally must be disclosed. Even without a radon-specific statute, most general property disclosure forms ask about known environmental hazards.

How much does it cost to fix a radon problem?

A standard sub-slab depressurization system typically costs $800–$2,500, averaging around $1,200, and usually installs in about a day.

Will radon stop my house from selling?

No. It's a fixable, well-understood issue. It can slow down or complicate a financed sale if it surfaces during a buyer's inspection and needs to be negotiated, but it doesn't typically kill a deal outright.

Does selling to a cash buyer mean I don't have to deal with radon at all?

You still have to disclose what you know, but a cash buyer can typically purchase the property as-is and handle mitigation themselves, skipping the negotiation and contractor-scheduling delay a financed sale often requires.

Are some states or areas more likely to have radon?

Yes — the EPA's Radon Zone map shows some counties have meaningfully higher typical levels than others. Check your specific county on EPA's official map rather than assuming based on your state alone.