Radon Laws in Michigan: Testing, Disclosure & Mitigation Rules

The Short Answer

Michigan regulates radon primarily through mandatory real estate seller disclosures and targeted residential building code requirements in high-risk counties. Under the Michigan Seller Disclosure Act (MCL § 565.957), residential home sellers must complete a statutory disclosure statement disclosing known environmental hazards, including radon gas and historical test data. Michigan does not license radon testers or mitigators through a dedicated state radon board, instead directing the public to national NRPP and NRSB certification registries. In new residential construction, the Michigan Residential Code enforces mandatory passive radon-resistant construction across nine southern EPA Zone 1 counties.

Testing Requirements

Indoor radon testing is voluntary for private single-family homeowners and residential landlords in Michigan; state law does not compel property owners to test existing residential dwellings prior to leasing or sale. Similarly, Michigan does not impose a statewide statutory mandate requiring regular radon screening in public K-12 schools or licensed childcare facilities, although the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and local health departments actively encourage voluntary school testing using standardized EPA protocols.

Real-Estate Disclosure

Real estate disclosure is codified under the Michigan Seller Disclosure Act, Michigan Compiled Laws (MCL) §§ 565.951 to 565.966. Under MCL § 565.957, sellers of residential real property (1 to 4 units) must deliver a completed Seller’s Disclosure Statement to prospective buyers before executing a binding purchase agreement. Section 10 of the statutory form specifically requires the seller to disclose knowledge of any environmental hazards on the property, explicitly listing radon gas alongside lead, asbestos, and underground tanks. While sellers must truthfully disclose known historical test results or installed mitigation systems, the act does not require sellers to perform testing as a condition of sale, leaving testing contingencies to purchase agreements.

Mitigator & Tester Certification

Michigan has no direct state licensing requirement specifically for radon mitigators or testing contractors, per the Michigan Department of Environment, Great Lakes, and Energy, verified November 2026. EGLE does not administer an independent state radon licensing exam or board. Instead, EGLE officially recommends that property owners hire contractors who maintain active national certifications through the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). However, contractors installing mitigation systems must comply with Michigan Department of Licensing and Regulatory Affairs (LARA) trade regulations, obtaining residential builder or maintenance and alteration licenses and local electrical permits for fan wiring.

New Construction

Radon-resistant new construction is mandatory in designated regions under the Michigan Residential Code (incorporating IRC Appendix F). Michigan mandates passive radon-resistant new construction (RRNC) techniques—including gas-permeable aggregate or soil-gas matting, 6-mil polyethylene ground retarders, foundation sealing, and a continuous vertical vent pipe—across nine designated EPA Zone 1 counties: Branch, Calhoun, Cass, Hillsdale, Jackson, Kalamazoo, Lenawee, St. Joseph, and Washtenaw. In all other Michigan counties, RRNC remains voluntary unless adopted by local municipal ordinance.

Radon Zones & the Action Level

According to the EPA Map of Radon Zones, Michigan contains nine EPA Zone 1 (High Potential) counties located in the southern tier, where predicted average indoor screening levels exceed the national action level of 4.0 pCi/L. Central and northern Lower Peninsula counties and parts of the Upper Peninsula are classified as Zone 2 (Moderate Potential, 2.0 to 4.0 pCi/L) or Zone 3 (Low Potential, < 2.0 pCi/L). EGLE enforces the federal EPA action level benchmark of 4.0 pCi/L, advising that mitigation systems be installed when indoor levels meet or exceed 4.0 pCi/L. For complete county breakdown, consult our EPA Radon Zone Map guide.

The State’s Radon Program

The state regulatory and educational authority is the Michigan Department of Environment, Great Lakes, and Energy (EGLE) Radon Program, managed within the Remediation and Redevelopment Division. EGLE provides technical assistance, coordinates with local health departments, maintains public information on certified contractors, and helps residents purchase low-cost short-term and long-term test kits. Homeowners can order test kits and access educational resources through the official EGLE Radon Program portal or by calling the state radon hotline at 800-723-6642 (800-RADON-GAS).

Sources & Limits

This regulatory guide is provided for educational and informational purposes only and does not constitute formal legal, building code, or engineering counsel. State statutory disclosure requirements and building codes are subject to legislative amendment. Property buyers, sellers, landlords, and contractors should verify current rules directly with EGLE or a qualified Michigan real estate attorney.

Official Sources: Michigan Compiled Laws § 565.957; Michigan Residential Code Appendix F; Michigan Department of Environment, Great Lakes, and Energy (EGLE); U.S. Environmental Protection Agency.

To review how Michigan’s policies compare with other jurisdictions, explore our nationwide guide to radon regulations across the United States or inspect the EPA Radon Zone Map.