Montgomery County, MD Accessory Structures: ADU Owner Occupancy (2026)
Key Facts
- Governing law
- Montgomery County Code § 29-19(b)
- License type
- Class 3 accessory apartment license
- Proof accepted
- MD tax return, license, or tax bill
- Enforcing office
- Dept. of Housing and Community Affairs
Summary
An accessory dwelling unit rental license requires the owner to live in either the main house or the ADU as their primary residence, proven with tax or license records.
the principal dwelling or accessory dwelling unit is the primary residence of the applicant for an accessory dwelling unit rental license. Evidence of primary residence includes: (i) the owner's most recent Maryland income tax return; (ii) the owner's current Maryland driver's license; or (iii) the owner's real estate tax bill for the address of the proposed accessory dwelling unit
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
Montgomery County will not license an accessory dwelling unit for rent unless the principal dwelling or the ADU itself is the applicant's primary residence. The Department of Housing and Community Affairs accepts a Maryland income tax return, a Maryland driver's license, or a real estate tax bill for the property as proof. At renewal, the owner must again attest that one of the two units on the lot is their primary residence, on top of certifying compliance with occupancy limits under Section 26-5.
Violations & Fines
Failing to prove owner-occupancy blocks issuance or renewal of the Class 3 rental license; operating an unlicensed ADU rental is a class A civil violation enforced by the County Attorney.
Frequently Asked Questions
Do I have to live in the ADU itself, or just the property?
What counts as proof of primary residence?
Sources & Official References
Other rules in Montgomery County
Compare Montgomery County to another location·View the Maryland accessory structures overview
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