County test age
Provide a result from less than three years before the lease date for covered ground-contact or basement rentals.
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Home/Radon Testing/Montgomery County, MD
Rental properties, property managers & homeowners
Radon testing for property management companies, landlords and homeowners. Plan testing for lease renewals, rental turnovers and multiple properties with a team that works directly with Grady Management, Inc.
RealPage vendor credentialing completed as required for our work with Grady.
4.9 rating, over 4,000 reviews NRSB-certified technicians Serving all of Montgomery County
Request a property management quote Call (703) 450-6398 Rental testing requirements
Experience with property management teams
From apartment communities to individual rentals, we help management teams plan professional radon testing around unit access, lease deadlines and report dates.
We work directly with Grady Management, Inc., based in Silver Spring, Maryland, and have performed radon testing for Grady-managed properties.
Experience coordinating with a property management company.
NextDay Inspect is credentialed through RealPage Vendor Credentialing, as required for our work with Grady.
Tell us your management company so we can confirm its specific onboarding requirements.
Know the dates before the next lease
For covered rentals, the test date matters at lease signing. County guidance includes both new leases and renewals.
Provide a result from less than three years before the lease date for covered ground-contact or basement rentals.
The qualifying result must be below the threshold. An existing mitigation system does not waive testing.
Use a radon professional, certify the required information in the lease or addendum, and provide the EPA tenant pamphlet or approved equivalent.
Covered units include single-family and multifamily rentals, including rental condominiums. Read Montgomery County DHCA guidance.
A separate two-year rule applies. Covered at- or below-grade rentals need a result within two years at lease signing. Confirm the property’s jurisdiction before setting its testing calendar. Rockville requirements.
Initiate follow-up testing within 14 days of the tenant’s notice. Within 90 days after confirmed results, reduce radon below 4 pCi/L and provide final professional test results to the tenant. Disclosure obligations also apply. County Code § 29-35E.
Requirements reviewed September 13, 2026.
From scheduling to the lease file
Send addresses, unit numbers, existing test dates and upcoming lease deadlines. Include the jurisdiction and any mitigation systems.
Identify your onsite contact and access arrangements. Plan monitor placement, collection and closed-house instructions with occupants.
Retain the written result with the address and unit, then review its age before the next lease signing. Arrange follow-up testing after mitigation when needed.
Several units or buildings?
We will confirm the monitor plan, access schedule and price for your assignment.
A radon test in Montgomery County is $185, or $175 when it is added to a home inspection. The single-residence price includes both visits, the monitor for the full 48 hours, and the written report with every hourly reading in it. The standard price covers one residence. Multiunit or multi-building work, including covered rental portfolios, needs a confirmed scope and price.
Day 1
Drop-off
A technician places it on the lowest level that could be used regularly, following EPA placement limits and the intended use of the space, inside a two-hour arrival window. With a home inspection, placement happens during the inspection visit.
48 hours
The house stays closed
For a short-term real-estate test, EPA guidance calls for closed-building conditions for at least 12 hours before the test and throughout the measurement. Windows stay closed, exterior doors open only for normal entry and exit, and the monitor logs hourly readings that help document the test conditions during the minimum 48-hour measurement.
Day 3
Pick-up and report
A technician picks the monitor up in another two-hour window and pulls the full record on the spot. The written report reaches you the same day.
NRSB-certified technicians. Our own team, certified by the National Radon Safety Board, not a subcontractor.
EPA testing guidance. Placement, closed-house conditions and the 48-hour minimum follow it, and your average is read against the EPA action level of 4.0 pCi/L.
Continuous monitors. Airthings Corentium Pro instruments, logging every hour for the whole test.
Appointment times are requests until our team confirms them. What the number means, how to prepare the property and the eight questions everyone asks are on the radon testing page; this page is about Montgomery County.
A measurement for your property
Montgomery County DEP identifies the county as a Zone 1 area and recommends testing every home. A county designation cannot tell you the radon level inside a particular rental unit. Testing provides that property’s result.
Our written report includes hourly readings from the continuous monitor. Keep the result with the property record and use it to plan the next step.
Local service, across your portfolio
Radon testing for rental properties and homes throughout Montgomery County. Explore your community or send us your property list.
Rockville, Gaithersburg and Takoma Park are incorporated municipalities in Montgomery County. Chevy Chase includes several distinct municipalities and unincorporated areas. Municipality status does not by itself settle which radon rule applies.
We do not install radon systems, so we have nothing to gain from your number. If the result is at or above the EPA action level of 4.0 pCi/L, you choose who fixes it. Once the system is in, we can test again and tell you what it reads.
Maryland’s residential disclosure framework includes radon among the hazardous or regulated materials covered by an owner’s actual knowledge for certain single-family residential property of four or fewer units. The statute has enumerated exemptions and does not itself require a radon test. County and municipal requirements may differ, so check the rules for the property’s location and type before relying on an existing result.
Md. Real Property section 10-702. Current as of September 2026. General information, not legal advice.
No. DEP presents it as County-level potential and recommends testing every home. Use the result measured inside the residence for a property decision.
For covered county rentals, the result must be less than three years old at lease signing; DHCA includes new leases and lease renewals. Rockville has a separate two-year rule for covered rentals. Check the exact jurisdiction and test date before scheduling.
Chevy Chase includes several municipalities, neighborhoods and unincorporated areas. A postal label alone does not establish the government, planning authority or radon rule for the property.
List each address and unit, the applicable jurisdiction and the occupant or access contact. The standard service covers one residence, so a multiunit assignment needs its monitor plan and price confirmed.
Yes. NextDay Inspect works directly with Grady Management, Inc. and has performed radon testing for Grady-managed properties. Contact us to discuss the scope and access needs of your rental portfolio.
Yes. We are credentialed through RealPage Vendor Credentialing as required for our work with Grady Management. Requirements are specific to each management company, so we confirm the onboarding requirements for your assignment.
The county rule is tied to lease signing and test age, rather than a blanket annual testing requirement. Covered new leases and renewals need qualifying results less than three years old. Existing tenancies and elevated results can create separate testing obligations.
Yes. DHCA says an existing mitigation system does not waive the lease-related testing requirement. A qualifying result must show a concentration below 4 pCi/L and meet the applicable test-age requirement.
Managing rental properties? Request a portfolio quote or call (703) 450-6398. Individual home tests can also be booked online.
Schedule a radon test Request a portfolio quote
NextDay Inspect
46179 Westlake Dr, Ste 200, Sterling, VA 20165
(703) 450-6398