Montgomery County Rental Radon Requirements
Educational guidance for Montgomery County landlords, tenants, and property managers on local rental-property radon testing, disclosure, and mitigation requirements.
Reviewed by Daisy Rezende, NRPP Radon Measurement Professional.
Montgomery County’s rental radon rules are local requirements for qualifying rental housing. They are not a statewide Maryland rental rule, and property managers should use the County’s current housing guidance and lease materials for the details that apply to a specific unit.
What County guidance covers
The County states that its requirements apply to ground-contact or basement units of residential rentals in single-family homes or multifamily dwellings, including condominiums. The County also describes the requirements as applying to multifamily and single-family rental housing.
The effective date listed in the County’s enacted Bill 26-22 materials is July 1, 2023.
Testing, timing, and cost
County housing guidance states that a landlord must have a radon test performed within three years before leasing a unit to a prospective tenant, and that the landlord is responsible for testing cost.
For new leases and lease renewals, the County describes providing test-result information and required lease certification or addendum materials. Use the current County page and sample addendum rather than a generic form.
Existing tenants and action levels
The County guidance describes a path for an existing tenant to conduct or hire a test and to notify the landlord in writing when a reported radon hazard reaches the stated action level. It also addresses the landlord’s subsequent responsibilities.
Mitigation, disclosure, and tenant-right details are fact-specific. Read the County’s current requirements and consult an appropriate legal or housing professional when you need advice about compliance or a dispute.
Educational information, not legal advice
Local code, agency guidance, and property facts can change how a requirement applies. Review the current official source and seek qualified legal or housing advice for a compliance question.
Authoritative sources
Primary County housing guidance, including lease and landlord information.
County legislative record for the enacted local law.
Related radon resources
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