Montgomery County, MD Accessory Structures: ADU Rental Restrictions (2026)
Key Facts
- License required
- before renting an ADU out
- Occupancy cap on renewal
- 2 residents over age 18
- Primary residence proof
- tax return, license, or tax bill
- Enforcing agency
- Dept. of Housing and Community Affairs
- Unlicensed rental penalty
- class A violation
Summary
Montgomery County requires a separate license before renting out an accessory dwelling unit, and caps occupancy at two adult residents unless the owner or the ADU serves as the applicant's primary residence.
An owner of a lot or parcel in a zone that permits accessory dwelling units must obtain a license to operate an accessory dwelling unit to live in or to rent if: ... (B) the principal dwelling or accessory dwelling unit is the primary residence of the applicant for an accessory dwelling unit rental license.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-90: Montgomery County Code contains legislation effective through May 7, 2026 | Zoning Updated Effective: April 13, 2026 | COMCOR Regulations effective as of July 1, 2026).
Full Breakdown
Under Montgomery County Code § 29-19(b), an owner in a zone that permits accessory dwelling units must obtain an ADU rental license from the Department of Housing and Community Affairs before renting the unit out. The Director requires proof the principal dwelling or the ADU is the applicant's primary residence, verified through a Maryland tax return, driver's license, or tax bill, plus a certification the ADU doesn't violate any HOA governing documents. On renewal the owner must attest occupancy will not exceed 2 residents over age 18 in the accessory unit. Rockville, Gaithersburg and Takoma Park run their own zoning and licensing, so their ADUs fall outside this County process.
Violations & Fines
Operating an ADU rental without the license is a class A violation under § 29-18(a); the County Attorney can also seek a civil injunction to shut down unlicensed rentals.
Frequently Asked Questions
Do I need a license to rent out my ADU in Montgomery County?
Is there an occupancy limit for a rented ADU?
Sources & Official References
Other rules in Montgomery County
Compare Montgomery County to another location·View the Maryland accessory structures overview
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