Maryland

Maryland has seen growing momentum for accessory dwelling units, with Montgomery County, Howard County, and the city of Baltimore all adopting ADU-friendly policies. The state's proximity to the DC job market makes ADUs an attractive option for rental income. ADU Pass helps Maryland homeowners handle the permit process.

646 ZIP codes
25 Counties
369 Cities

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State ADU details

State ADU law

Maryland enacted statewide ADU preemption with the Accessory Dwelling Units Act of 2025 — HB 1466 / SB 891 (cross-filed) — passed by the General Assembly in the 2025 Regular Session and effective 2025-10-01. Counties and municipalities with planning and zoning authority must adopt local laws compliant with the Act by 2026-10-01. The Act establishes that it is the policy of Maryland to promote and encourage ADU creation on land with a primary single-family detached dwelling. ADUs are defined as secondary units on the same lot/parcel/tract as a primary single-family detached dwelling, no greater than 75% of the size of the primary dwelling. Counties and municipalities cannot prohibit ADUs or impose unreasonable restrictions on their construction or rental. The 2025 ADU Act ALSO amends the Maryland HOA Act (Title 11B of the Real Property Article), prohibiting community associations from prohibiting or unreasonably restricting ADU construction and rental. The state has been preparing this framework since 2023 (SB 382 created the ADU Policy Task Force, which issued its final report 2024-05-31).

checked 2026-05-20

State HOA preemption

Maryland enacted HOA preemption for ADUs as part of the 2025 ADU Act. HB 1466 / SB 891 amended the Maryland Homeowners Association Act (Real Property Article, Title 11B), adding the ADU definition at §11B-101(a-1) and prohibiting HOAs from prohibiting or unreasonably restricting the construction or rental of ADUs on lots with primary single-family detached dwelling units. HOAs retain authority to (a) treat an ADU as a separate lot for voting and assessment purposes (optional, not required) and (b) impose reasonable design and architectural standards consistent with the community's overall character. The HOA preemption became effective 2025-10-01.

checked 2026-05-20

State financing programs

Maryland does not currently operate an ADU-specific statewide loan, grant, or forgivable-loan program tied to the 2025 ADU Act. The Maryland Department of Housing and Community Development (DHCD) administers a broad portfolio of homeownership, rental development, and home-repair financing — including the Maryland Mortgage Program, Settlement Downpayment Loan Program, Project Restore (commercial-to-residential conversions), and various Energy & Home Repair loan products. None target ADU construction directly, though Project Restore can fund ADU-like conversions, and the Energy & Home Repair Loan can fund ADU-related electrical, HVAC, and weatherization upgrades.

checked 2026-05-20

State insurance regimes

Maryland operates a FAIR Plan as the insurer of last resort, the Maryland Joint Insurance Association (MDJIA), which is the state-administered Maryland Property Insurance Availability Program. MDJIA provides Homeowners, Dwelling, and Commercial property coverage to applicants who have been unable to obtain coverage through the voluntary admitted market. Coverage includes fire, windstorm, hail, vandalism, and civil commotion. Coastal Maryland (Eastern Shore counties along the Atlantic and Chesapeake Bay) faces wind and water exposure; many policies in coastal areas carry hurricane- or wind-deductibles separate from the standard deductible. Mobile and manufactured homes in coastal Maryland have experienced significant carrier withdrawal in 2024-2026, increasing reliance on MDJIA. ADUs are typically covered as accessory structures under standard homeowner policies (often at ~10% of dwelling coverage) or require a dwelling-fire or landlord endorsement when rented; MDJIA covers eligible properties on the same homeowner / dwelling-fire basis without ADU-specific provisions.

checked 2026-05-20

State housing programs

Maryland's primary state-level ADU program is the 2025 ADU Act framework: statewide preemption requiring local jurisdictions to adopt compliant ordinances by 2026-10-01, including HOA preemption. The Maryland Department of Planning maintains an ADU resource hub with technical assistance for local governments. Maryland does not currently operate a statewide pre-approved ADU plan catalog, an ADU rebate, or an impact-fee waiver statute, but the local-compliance window through 2026-10-01 is expected to produce additional ADU-specific incentive programs.

  • ADU Act 2025 Statewide Floor (HB 1466 / SB 891) — Counties and municipalities with planning/zoning authority must adopt compliant ordinances by 2026-10-01, allowing ADUs on every single-family-detached lot at up to 75% of primary dwelling size. Bars prohibitions and unreasonable restrictions. Includes HOA preemption.
  • Maryland Department of Planning ADU Resource Hub — Resource hub with model ordinances, FAQs for local governments (HB 1466 FAQ), task-force final report, and statewide ADU ordinance inventory.
checked 2026-05-20

Known state issues (3)

  • policy-review (since 2025-10-01) — ADU rules in any given Maryland jurisdiction are in flux through 2026-10-01. Practitioners should confirm both the state floor and local-implementation status before relying on local code language alone, and should re-check local code shortly after 2026-10-01 for newly adopted ordinances. (source)
  • other (since 2024-01-01) — Coastal-county ADU pro forma should assume elevated premium exposure and the possibility of MDJIA-only carrier availability. (source)
  • other (since 1851-01-01) — Consumers querying for Maryland counties should not assume Baltimore City rolls up into Baltimore County. The two are separate jurisdictions with separate ADU ordinances under HB 1466 / SB 891. (source)
Federal (United States) — ADU-relevant rules and programs

Federal ADU law

The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.

checked 2026-04-20

Federal financing programs

Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.

checked 2026-04-20

Federal tax credits

There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.

checked 2026-04-20

Federal housing programs

HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.

checked 2026-04-20

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