At a glance: where each county stands
Maryland's HB 1466 (2025) gave every county until October 1, 2026 to adopt local ADU rules. Here is where the five counties we serve stand right now — verified against official county sources on October 1, 2026.
Charles County: enacted. Bill 2026-06 passed unanimously on July 7, 2026 and is now in the county code (§3.01.700). No further votes pending.
Prince George's County: in committee. CB-092-2026 was moved favorable as amended in September 2026. No final vote date published.
Montgomery County: current law plus pending changes. ADUs have been allowed since 2019; ZTA 26-06 would rewrite the standards (vote outcome unconfirmed), and Bill 41-26 — which would end the owner-occupancy rule — has a public hearing scheduled October 6, 2026 at 1:30 p.m.
St. Mary's County: by-right under existing law. ADUs are already allowed under zoning ordinance §51.3.108. A 2026 update for the state law is unconfirmed.
Calvert County: proposed, not final. Text Amendment 25-07 was recommended by the Planning Commission; the county board's final vote has no published date.
Charles County
Vote status: enacted — Bill 2026-06 passed July 7, 2026 (unanimous), codified at §3.01.700.
Next milestone: none — the law is in effect.
Council meetings: the Board of County Commissioners holds regular legislative sessions on the 1st and 3rd Tuesday or Wednesday of each month.
Permit office: Department of Planning & Growth Management — 301-645-0692, [email protected].
Agendas: CharlesCountyMD.gov/CommissionerMeetings.
Full rules: Charles County ADU rules explained.
Sources: Bill 2026-06 passage (Star 98.3 FM, July 7, 2026); codified text (ecode360.com §3.01.700).
Prince George's County
Vote status: in committee — CB-092-2026 moved favorable as amended (PHED committee, September 2026). Final enactment unconfirmed.
Next milestone: no date published for the final vote.
Council meetings: Tuesdays at 10:00 a.m. in Largo; legislative sessions on the 1st and 3rd Tuesday.
Permit office: Department of Permitting, Inspections, and Enforcement (DPIE) — 301-636-2050 for building permit questions; [email protected] for electronic plan review. We could not verify a general DPIE email — the county routes most contact through phone and its online portal.
Agendas: princegeorgescountymd.legistar.com.
Full rules: Prince George's County ADU rules explained.
Sources: PHED committee action (Sept 2026 committee summary); DPIE building-permits page.
Montgomery County
Vote status: two bills in motion. ZTA 26-06 (ADU standards rewrite): a vote was expected September 15, 2026, but we could not confirm the outcome — the county's own tracker is out of date. Bill 41-26 (would remove the owner-occupancy requirement): public hearing scheduled October 6, 2026 at 1:30 p.m.
Next milestone: October 6, 2026 hearing (Bill 41-26, scheduled); no published date beyond that.
Council meetings: generally Tuesdays starting 9:00/9:30 a.m.; committee sessions Monday and Thursday.
Permit office: Department of Permitting Services — dial 311 in-county or 240-777-0311. We could not verify a direct public email; the county routes contact through 311.
Agendas: montgomerycountymd.gov/CCM/councilsessions.html.
Full rules: Montgomery County ADU rules explained.
Sources: County ZTA tracker (note: stale as of Oct 2026); Department of Permitting Services.
St. Mary's County
Vote status: existing law — ADUs are already allowed by-right under zoning ordinance §51.3.108 ("Accessory Apartment"). Whether the county adopted a 2026 update for the state mandate is unconfirmed.
Next milestone: not published.
Council meetings: Commissioners of St. Mary's County meet Tuesdays at 9:00 a.m. in Leonardtown; evening public hearings commonly at 6:30 p.m.
Permit office: Department of Land Use and Growth Management — 301-475-4200 x71500, [email protected].
Agendas: stmaryscountymd.gov (meeting documents portal).
Sources: Maryland Dept. of Planning ADU ordinance inventory; St. Mary's County meeting minutes (2026).
Calvert County
Vote status: proposed, not final — Text Amendment 25-07 was recommended unanimously by the Planning Commission, but the Board of County Commissioners' final vote has no published date.
Next milestone: no date published.
Council meetings: Board of County Commissioners meets Tuesdays at 10:00 a.m. in Prince Frederick; the agenda posts the Thursday before.
Permit office: Department of Planning & Zoning, Office of Inspections & Permits — 410-535-2155 (residential permits ext. 2244), [email protected].
Agendas: calvertcountymd.gov Agenda Center.
Sources: TA 25-07 exhibits (choosecalvert.com); Planning Commission recommendation (~Aug 2025).
Why this page exists
ADU rules are being written in real time. A blog post from last year — or even last month — can be wrong today. Bookmark this page: it is the one page we refresh every time a county votes. And when you are ready to act on your lot, run our lot checker or call the county office above — one call settles what a hundred articles cannot.