Local Radon Requirements in Maryland
A jurisdiction-specific guide to Montgomery County, Rockville, and Gaithersburg radon requirements. Local rules vary by property type and transaction.
Reviewed by Daisy Rezende, NRPP Radon Measurement Professional.
Radon requirements are not one statewide rule that applies identically across Maryland. Property type, whether a home is being sold or rented, and the local jurisdiction can change what applies. Use this hub to start with the right local resource, then confirm the current official requirement before acting.
Start with the property and jurisdiction
A sale, a new lease, an existing tenancy, and a multifamily property can each be governed differently. Montgomery County, the City of Rockville, and the City of Gaithersburg should not be treated as interchangeable simply because they are geographically related.
This resource is educational information, not legal advice. The linked government materials are the controlling starting point for current local requirements.
- Montgomery County rental requirements
- Montgomery County home-sale requirements
- Rockville sale and rental requirements
- Gaithersburg city-code and rental-program references
Montgomery County resources
Montgomery County publishes separate guidance for qualifying rental housing and for qualifying home sales. The rental guidance addresses testing, disclosure, and mitigation obligations. The home-sale guidance addresses qualifying single-family homes and townhomes, with stated exclusions and municipal exceptions.
City requirements may be separate
Rockville publishes its own radon information for qualifying rentals and home sales. Its requirements should be read as Rockville-specific, not as a statewide rule.
For Gaithersburg, the City’s current code and rental-housing materials are linked below. A current City page establishing a radon-specific testing interval or property scope was not independently verified during this work, so this site does not infer one.
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
County housing guidance for rental-property testing and mitigation.
County environmental guidance for qualifying home sales.
City overview of local sale and rental rules.
City source for current municipal code materials.
Related radon resources
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