Maryland
Buying Land in Montgomery County, Maryland
Seat Rockville. Montgomery is really two counties in one: a dense, wealthy Washington DC suburb across its southern and eastern two-thirds, and a nearly 93,000-acre Agricultural Reserve across its northern and western third, downzoned and protected by a transferable development rights program since 1980. Which side of that line a parcel sits on changes almost everything about what you can build.
A county split in two: dense DC suburb, and a protected farmland third
Montgomery County's southern and eastern two-thirds -- Bethesda, Silver Spring, Rockville, Gaithersburg -- are among the most densely developed, highest-cost suburban land in Maryland, built out under the county's ordinary residential, commercial, and mixed-use zoning categories administered by the Montgomery County Planning Department (part of the bi-county Maryland-National Capital Park and Planning Commission, which Montgomery shares with Prince George's County). That reputation as wealthy DC suburbia is accurate for most of the county's land area by parcel count and population, but it describes only part of Montgomery's actual footprint.
The northern and western third of the county tells a different story. In 1980, facing the same development pressure radiating out from Washington that has since consumed farmland in neighboring counties, the Montgomery County Council designated roughly 93,000 acres -- close to a third of the county's total land -- as a permanent Agricultural Reserve. That decision, and the transferable development rights (TDR) system built to make it politically and economically workable, is now one of the most studied and longest-running farmland preservation programs in the United States. A buyer looking at raw land in Montgomery County needs to know immediately which of these two Montgomery Counties a specific parcel actually sits in, because the zoning, density, and realistic use of the land differ enormously between them.
Inside the Agricultural Reserve: 25-acre density and a transferable development rights system
Before 1980, most of what's now the Agricultural Reserve carried a Rural Zone designation allowing one house per 5 acres -- density high enough that, left unchecked, it would have eventually converted the area to large-lot suburban sprawl rather than working farmland. The 1980 legislation created a new Rural Density Transfer (RDT) zone across most of the Reserve, cutting by-right density to one house per 25 acres, while simultaneously granting every RDT-zoned property one transferable development right (TDR) per 5 acres of land under the zone's original density -- meaning a Reserve landowner who agrees never to develop beyond the 25-acre floor can instead sell those TDRs to developers building at higher density in the county's designated growth areas elsewhere.
The program has real, ongoing traction: a 2023 Montgomery County Office of Legislative Oversight report put total acreage preserved specifically through the TDR mechanism at 47,903 acres as of 2022 -- a large number, though smaller than (and not the same figure as) the roughly 93,000-acre Reserve boundary itself, since not every acre inside the Reserve has sold its TDRs or is otherwise permanently restricted. For a buyer, that distinction matters: a specific Reserve parcel could be at its full 25-acre-minimum density with development rights intact, or it could already have sold its TDRs (a status that runs with the land, like a conservation easement). See our dedicated farmland standalone on Montgomery County's Agricultural Reserve for what to check on a specific parcel before assuming either scenario.
Beyond the Ag Reserve: a pioneering affordable-housing set-aside on ordinary development
Separate from the Agricultural Reserve entirely, Montgomery County has required, since a law took effect January 21, 1974, that most new residential developments of 20 or more units -- anywhere in the county, most relevantly in the suburbanized two-thirds outside the Reserve where subdivision-scale housing actually gets built -- set aside 12.5% to 15% of units as Moderately Priced Dwelling Units (MPDUs): affordable, income-restricted homes sold or rented under county-regulated terms. It's widely credited as one of the first successfully implemented mandatory inclusionary zoning programs in the country, and it has produced more than 12,000 affordable units since inception.
If you're evaluating land specifically to build 20 or more homes, this is a direct cost and design factor to build into your plan from the outset, including a 30-year resale-control period on MPDU units after initial sale. See our dedicated housing-mitigation-requirements page for Montgomery County for the program's current set-aside percentages, income thresholds, and resale rules -- including a 2025-2026 county policy review that may change some of these terms.
Government, Critical Area, and septic/well basics
Montgomery is a charter county under a Council/Executive structure adopted by referendum in 1968 and implemented in 1970: an 11-member County Council (nine district seats added by a 2016 charter amendment, plus two at-large) holds legislative and zoning authority, while a separately elected County Executive administers the county government -- a structure shared with only eight other Maryland counties rather than the traditional Board of County Commissioners model most Maryland counties still use. Zoning itself, both inside and outside the Ag Reserve, is administered through the Montgomery County Planning Department, part of the Maryland-National Capital Park and Planning Commission (M-NCPPC), a bi-county agency Montgomery shares with Prince George's County -- a genuinely distinctive arrangement not found in most other Maryland counties.
One thing that simplifies research here relative to most of the rest of Maryland: Montgomery County has no Chesapeake Bay Critical Area territory at all, because the Potomac's tidal/nontidal boundary sits at Little Falls, downstream in the District of Columbia -- so a Montgomery parcel is never subject to the added IDA/LDA/RCA overlay described on our Maryland state page. Septic and well permitting still follow the statewide COMAR 26.04.02 and 26.04.04 standards administered by the Montgomery County Department of Health and Human Services as the local Approving Authority, the same as everywhere else in Maryland.
Who to Call Before Buying Land in Montgomery County
Direct WebFetch to montgomerycountymd.gov was blocked by this session's network egress proxy, so department names, current fees, and turnaround times should be confirmed directly. Zoning for both the ordinary suburban districts and the Agricultural Reserve runs through the bi-county M-NCPPC Planning Department rather than a standalone county planning office.
Planning & Zoning
Montgomery County Planning Department (M-NCPPC)
Zoning district lookups, the Agricultural Reserve/RDT zone, and subdivision review.
Other
Montgomery County Office of Agriculture
Agricultural Reserve program details and questions about a specific TDR sale or RDT-zoned parcel.
Other
Montgomery County Department of Housing and Community Affairs (DHCA)
Current MPDU set-aside percentages, income limits, and resale-control rules for any development of 20+ residential units.
Septic / Onsite Wastewater
Montgomery County Department of Health and Human Services
Septic (COMAR 26.04.02) and well construction (COMAR 26.04.04) permitting.
GIS / Parcel Records
Montgomery County GIS / MC Atlas
Parcel boundary lookups, zoning maps, and Agricultural Reserve boundary layers.
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Get local guidanceTopics Specific to Montgomery County
Sources
- About County Government — Montgomery County, MD (accessed 2026-09)
- Agricultural Land Preservation - Office of Agriculture — Montgomery County, MD (accessed 2026-09)
- Transferable Development Rights and Building Lot Termination Programs (OLO Report 2023-1) — Montgomery County Office of Legislative Oversight (accessed 2026-09)
- Forgotten Frontier: Montgomery County's Agricultural Reserve — LerchEarlyBrewer (accessed 2026-09)
- Montgomery County Agricultural Reserve — Wikipedia (accessed 2026-09)
- FIPS Code 24031 -- Montgomery County, Maryland — FipsDecoder (accessed 2026-09)
- Chesapeake Bay, Maryland — Maryland State Archives (accessed 2026-09)
- Maryland Fishing Tidal / Nontidal Dividing Lines — eRegulations (accessed 2026-09)
- Moderately Priced Dwelling Unit (MPDU) Program — Montgomery County, MD (DHCA) (accessed 2026-09)
- County looks to revise moderately priced dwelling unit program — Bethesda Magazine (accessed 2026-09)
Last reviewed 2026-09