The bill amends Chapter 5-20.8 of the General Laws by introducing a new section that mandates radon inspection and mitigation for residential real estate transactions. It defines key terms such as "radon," "radon test," and "residential real estate transaction." A radon test must be performed no earlier than one year prior to the closing date for transactions not exempted under specific conditions. Exemptions include transactions involving foreclosures, certain sales by court-appointed trustees, and properties with existing radon mitigation systems that have been tested within the last three years.

The bill requires that if a radon test indicates unsafe levels, a radon mitigation system must be installed by a certified or licensed individual prior to the closing of the residential real estate transaction, if possible. If it is not possible to complete the work before closing, the estimated cost of the mitigation system must be held in escrow until the work is completed. The buyer is generally responsible for the cost of the radon test unless the seller provides a certified test indicating no unsafe radon levels completed within the past year. This act is set to take effect on June 1, 2027, establishing clear protocols for radon inspection in real estate transactions to ensure safety for future homeowners.