A bill for an act relating to radon mitigation requirements and tax credits, including retroactive applicability provisions, and making appropriations.

HF 2665 requires new single-family and two-family residential construction (after adoption) to include passive radon mitigation systems in the building code. It creates a tax credit of up to $1,000 for homeowners and renters to cover the cost of installing radon mitigation systems, applying retroactively to tax years beginning January 1, 2025. For rental properties, tenants can test for radon (with results ≥4 picocuries per liter triggering landlord action), and landlords must install mitigation systems within 90 days or face lease termination with rent refunds. The bill also appropriates $100,000 for free radon test kits available to homeowners and renters through the state health department.