Radon disclosure

A disclosure about known radon levels or testing in the home. Required in some states, optional in others. Radon is a naturally occurring gas that can build up in basements.

Disclosures · Updated September 2026

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Part 1 of 4

Why a seller cares

If you have tested for radon, or installed a mitigation system, the disclosure asks about it in many states. A past high reading with a system installed is a fully answered question; a past high reading with nothing done is an open one.

Part 2 of 4

A simple example

You tested five years ago at 5.8 pCi/L and installed a mitigation system. The disclosure says so, and the buyer's retest reads 1.1.

Radon disclosure: a simple example
What you knowWhat tends to follow
A high test and a system installedThe buyer retests, sees a low number, and moves on
A high test and nothing doneThe buyer asks for mitigation, and the disclosure says you knew
Never testedThe buyer tests during inspection; there was nothing to disclose

Disclosing a radon history with a fix attached ends the conversation.

Part 3 of 4

What people get wrong

That never testing avoids the issue. The buyer will test, and the only thing you avoid is knowing the number first.

Part 4 of 4 · where to read next

Where it appears in the sale

What a definition is, and what it isn't

Keighbor is a software company, not a law firm, brokerage, or tax adviser. This is general information, not legal, tax, financial, or real estate advice about your sale. Your situation may differ. Before acting on a contract, disclosure, title, tax, or pricing question, ask an appropriately licensed professional in your state.

Written and researched by Keighbor Research · drawn from the reference glossary · how we research and check what we publish

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