Radon Disclosure Requirements When Selling a Home in Indiana
What Indiana Law Requires Sellers to Disclose
Indiana's seller disclosure law is rooted in Indiana Code 32-21-5, which governs residential property disclosure statements. When you sell a home in Indiana, you are required to complete and deliver a Seller's Residential Real Estate Sales Disclosure form to potential buyers before they sign a purchase agreement. That form includes a direct question about radon: have you had the property tested, and if so, what were the results?
If you have had a radon test done at any point while owning the home, you must disclose the result. If a radon mitigation system was installed, you must disclose that too, along with any post-mitigation test results you have on file. The standard Indiana disclosure form, published by the Indiana Association of Realtors, asks specifically about:
- Whether a radon test has ever been performed on the property
- The result of that test, if one exists
- Whether a radon mitigation system is present
- Any known follow-up testing results after mitigation
Sellers are not required under state law to test before listing. The disclosure obligation applies to known results. But if you have test records, hiding or omitting them creates legal exposure. Buyers who later discover undisclosed elevated radon have grounds for misrepresentation claims under Indiana law.
Indiana Real Estate Markets and Radon Expectations
Radon is taken seriously in Indiana real estate transactions. The state is entirely in EPA Zone 1, the highest risk category, and experienced buyers and agents in every major market treat a radon test as a standard line item during the inspection contingency period.
Indianapolis Metro
In the Indianapolis metro, including Carmel, Fishers, Noblesville, Greenwood, and Zionsville, radon testing is effectively universal for home purchases. Marion County and the surrounding ring counties sit on deep glacial outwash and lake plain sediments from the Wisconsin glaciation, which makes elevated radon common. Buyers in the Indianapolis market routinely include radon inspection language in their offers. A test result above 4 pCi/L rarely kills a deal but almost always triggers a mitigation request or a price adjustment.
Fort Wayne
Fort Wayne and Allen County sit on thick glacial till deposits from the Wisconsin glaciation. ISDH data shows elevated test rates in this region. In the Fort Wayne market, radon comes up in most residential transactions. Local buyers are generally informed, and local agents are accustomed to negotiating mitigation as a standard repair item.
South Bend and Elkhart
Northern Indiana counties including St. Joseph, Elkhart, and LaPorte have some of the state's highest average radon levels due to dense glacial till deposits. South Bend buyers are accustomed to elevated results and often build radon contingency language into their offers. If you are selling in this market and have not previously tested, expect that the buyer's inspector will.
Bloomington and Monroe County: The Karst Caveat
Monroe County deserves special attention. Bloomington sits in the unglaciated karst belt of southern Indiana, an area underlain by porous limestone with sinkholes and caves. Radon behavior in karst geology is less predictable than in glacial till regions. The rock fractures and solution channels that characterize karst can allow radon to migrate from deeper sources into homes in irregular patterns. A neighbor's test result tells you less about your home's level in karst terrain than it would in Indianapolis or Fort Wayne.
Sellers in Monroe County, Lawrence County, Orange County, and Crawford County should test before listing if they have no existing data. Given the unpredictability of karst radon migration, buyers in these counties should insist on a test even if neighboring properties have tested low. The ISDH specifically notes the elevated testing variability in southern Indiana's karst region.
Buyer Protections Under an Indiana Purchase Agreement
Most Indiana residential purchase agreements include an inspection contingency that gives the buyer a window, typically 10 to 15 days, to conduct inspections including radon testing. During this period, a buyer can:
- Request repairs, including installation of a radon mitigation system
- Negotiate a credit at closing to cover the buyer's cost of mitigation after closing
- Request a price reduction reflecting the cost of remediation
- Terminate the contract without losing earnest money if the seller will not address the issue
If a seller has disclosed elevated radon on the disclosure form, buyers can still test and negotiate, but their ability to terminate depends on the specific contract language. Work with an experienced Indiana real estate agent who understands how radon requests are handled in your local market.
A key buyer protection: if a seller fails to disclose known radon information and the buyer discovers it after closing, Indiana courts have found grounds for misrepresentation claims. The disclosure requirement is not ceremonial. Keep your test records regardless of the result.
Seller Strategy: Test Before You List
Testing before you list is almost always the right move in Indiana. Here is why.
If you test and the result is below 4 pCi/L, you can disclose a clean result. That pre-empts one of the most common inspection contingency negotiations. Buyers who see a recent professional test showing 1.8 pCi/L are unlikely to make it a negotiation point.
If you test and find elevated radon, you can mitigate before listing. Mitigation in Indiana typically costs $800 to $2,000. A post-mitigation test showing levels below 2 pCi/L is a selling point. You present the home as already remediated, the disclosure shows a completed history, and buyers have less to negotiate over.
If you do not test and the buyer's inspector finds elevated radon, you are negotiating from a weaker position. The buyer has leverage during the inspection contingency period. In a competitive market, a seller credit demanded for radon mitigation often exceeds what the seller would have paid to mitigate proactively. In a slower market, the elevated reading can extend the transaction timeline or prompt requests that go beyond straight mitigation.
How Elevated Radon Affects Indiana Home Prices and Negotiations
Radon rarely kills a deal in Indiana, but it does affect negotiations. The typical pattern in Indianapolis, Fort Wayne, South Bend, and Bloomington works like this:
The buyer's inspector returns a result above 4 pCi/L. The buyer, through their agent, submits a repair request asking the seller to install a mitigation system prior to closing. The seller either agrees, offers a closing credit in lieu of installation, or splits the difference with a reduced credit. Deals proceed to close.
Where it gets more complicated: homes with very high readings (above 10 pCi/L or above 20 pCi/L) in markets where buyers have other choices. In those cases, buyers may push for both mitigation and a post-installation test confirmed before closing, adding time to the transaction. Some buyers also ask for a warranty on the mitigation system, which reputable Indiana installers typically provide.
In the Monroe County karst region, uncertainty about radon behavior sometimes prompts buyers to request a longer post-mitigation wait period before closing, or to ask for a second post-mitigation test. This is reasonable given karst's unpredictability.
ISDH Licensing and Who Can Test or Mitigate
Indiana requires all radon testers and mitigators operating for compensation to be licensed through the Indiana State Department of Health (ISDH). When a radon test is performed for real estate purposes, using a licensed professional protects both parties. An unlicensed test result has no standing in an Indiana real estate transaction and may not be accepted by the buyer's lender.
The ISDH maintains a list of certified radon professionals. For real estate transactions, use a professional certified by NRPP or NRSB and licensed through ISDH. Both certification programs accept test results for real estate use, and both are recognized by Indiana law.
Find a Licensed Radon Professional
If you need a radon test before listing or a mitigation system installed to satisfy a buyer's inspection request, start with professionals licensed through ISDH. Our directory lists radon professionals in Indiana by location, so you can find someone serving your area quickly.
Frequently Asked Questions
Does Indiana require sellers to disclose radon test results?
Yes. Indiana Code 32-21-5 requires sellers to complete a Seller's Residential Real Estate Sales Disclosure form that includes questions about known radon test results and any installed mitigation systems. If you have test records, you must disclose them.
Am I required to test my home for radon before selling it in Indiana?
No. Indiana does not require pre-listing testing. The disclosure obligation applies only to results you already have. However, testing before listing is usually the right strategy, because it lets you mitigate proactively or disclose a clean result before the buyer's inspector weighs in.
What happens if a buyer's inspection finds elevated radon in an Indiana home?
The buyer typically submits a repair request during the inspection contingency period, asking the seller to install a mitigation system or provide a closing credit. Most Indiana transactions resolve this without the deal falling through. Mitigation costs $800 to $2,000 in Indiana, which is manageable relative to most home prices.
Why is radon disclosure more complicated in Monroe County and southern Indiana?
Monroe County (Bloomington) and neighboring counties sit on limestone karst geology, which includes sinkholes, caves, and fractured rock. Radon migrates unpredictably through karst compared to the glacial till that dominates northern and central Indiana. Neighboring test results are less reliable as a guide, and buyers in this region should always test rather than relying on disclosure alone.
Can a buyer walk away from an Indiana home purchase because of radon?
Yes, if the purchase agreement includes a standard inspection contingency and the seller will not address elevated radon through mitigation or a price adjustment. In practice, most Indiana buyers and sellers negotiate a resolution rather than terminating. A properly installed mitigation system brings most Indiana homes well below the 4 pCi/L action level.