Radon in Indiana Rental Properties — Tenant and Landlord Guide

March 2, 2026

Most discussion of radon focuses on owner-occupied homes. But renters face the same exposure risk — and have fewer legal tools to address it. Indiana’s radon law covers professional licensing (mitigators and testers must be IPLA-licensed) but does not regulate landlord obligations to tenants. Here’s the practical situation for both sides of the rental relationship.

Indiana Law: What It Requires (and Doesn’t)

What Indiana law requires:

• Any professional performing radon testing or mitigation for compensation must hold an active IPLA radon license. This is a firm state law under 410 IAC 5.1.
• Sellers of real property must disclose known material defects under IC 32-21-5 — which may include elevated radon if previously documented (though courts have not specifically ruled on radon as a required disclosure).

What Indiana law does NOT require:

• Landlords are not required to test rental properties for radon.
• Landlords are not required to disclose radon test results (existing or historical) to tenants.
• Landlords are not required to remediate elevated radon in rental properties.
• There is no Indiana administrative rule treating elevated radon as a habitability violation.

This places Indiana among the majority of U.S. states, which have not enacted tenant-protective radon legislation. A handful of states (Illinois, Florida, and others) have enacted radon-specific landlord disclosure or testing requirements. Indiana is not among them.

Which Rental Units Are At Risk

Radon risk in rental housing is concentrated in the same way as owner-occupied housing: lowest levels of a building, over soil or a slab.

Highest risk:

• Ground-floor units and basement apartments in single-family homes, duplexes, and small multifamily buildings
• Any unit that sits directly over a basement, slab, or crawl space
• Older construction with incomplete foundation sealing

Lower risk:

• Second floor and above in apartment buildings (radon dilutes with each floor)
• Units in large, modern, mechanically ventilated buildings with HVAC systems that bring in fresh outdoor air

Key rule: If your unit is at or near ground level in an Indiana Zone 1 county — which covers most of the state — radon is worth testing for.

What Tenants Can Do

Test the Unit Yourself

A short-term radon test kit is non-invasive. You place a canister or small card in the lowest level of your unit, leave it for 48–96 hours under closed-window conditions, and mail it to a lab. The kit is not visible to a landlord, leaves no marks, and costs $15–30 at hardware stores or online.

Place the test in the lowest room where you spend significant time. If you have a basement apartment, test there. If you live on the ground floor, test there. Results come back in 2–4 weeks.

If Results Are Elevated

If your test comes back at or above 4 pCi/L, you have several options:

Talk to the landlord. Many landlords are willing to address radon once they understand the risk and the solution cost. A mitigation system for a residential property costs $1,200–$2,000 and is largely invisible — an outdoor pipe and a small fan. Frame the conversation as a habitability improvement, not a legal demand. Bring the test result, information about what mitigation involves, and cost estimates.

Document the request. Put the request in writing (email is fine). This creates a record if you later need to escalate or if the landlord sells the property.

Negotiate in your lease. If you are signing a new lease or renewing, ask for a radon testing and remediation clause. This can specify that the landlord will test within 60 days and mitigate if levels exceed 4 pCi/L. Not all landlords will agree, but many will — especially if you are otherwise a desirable tenant.

Contact local health authorities. Marion County (Indianapolis) and some larger Indiana counties have housing inspection programs. While Indiana law does not define elevated radon as a habitability violation, a health department officer may be willing to document the complaint or facilitate a conversation with the landlord.

Consider the lease terms. If the landlord refuses and your lease is up for renewal, elevated radon in your unit is a legitimate reason to relocate — particularly for households with children, smokers, or long-term residents.

What You Cannot Compel

Without specific lease language, Indiana tenants cannot legally compel a landlord to test or mitigate radon. There is no Indiana administrative process specifically for radon complaints in rentals. A habitability lawsuit based solely on elevated radon — without other housing code violations — would face significant legal hurdles in Indiana.

What Landlords Should Know

The Practical Case for Testing

Even without a legal mandate, there are practical reasons Indiana landlords should address radon proactively:

Liability exposure over time. While no Indiana case has yet established landlord radon liability, trends in other states suggest this will not remain the case indefinitely. A landlord who received written notice of elevated radon and took no action is in a weaker legal position than one who tested and mitigated.

Tenant retention. Long-term tenants who discover elevated radon mid-lease — particularly tenants with children — may terminate early or publicize the issue. The cost of a mitigation system ($1,200–$2,000) is often less than one month’s lost rent.

Property value. A mitigated property with documented results is more attractive to both tenants and eventual buyers. RRNC-ready or mitigated properties are increasingly expected in Indiana’s larger markets.

Section 8 / HUD properties. Some HUD housing assistance programs and state-funded housing programs are beginning to incorporate radon testing requirements into unit inspections. Landlords in these programs should verify current requirements with their local housing authority.

Professional Testing for Landlords

If you want to test your rental property professionally, hire a licensed Indiana primary radon tester. A certified measurement provides defensible documentation — useful if a tenant later makes a claim or if you sell the property.

Landlords testing multiple units should ask testers about multi-unit pricing, which is often discounted from single-unit rates.

Mitigation in Occupied Units

A licensed Indiana radon mitigator can install a sub-slab depressurization system with minimal disruption to a tenant. The work typically takes 4–6 hours. The only permanent exterior feature is a 4-inch PVC pipe running to the roofline or exterior wall. For most landlords and tenants, scheduling during a weekday works fine.

Browse licensed Indiana radon professionals — testers and mitigators — by county on this site.