Administrative overview · FIPS 24037
St. Mary's County permit authority
The first compliance decision is jurisdictional: identify the office with statutory authority over your parcel, then use its filing and inspection sequence to keep the project moving.
Jurisdictional status
County
This county profile is the primary starting point for unincorporated-area permitting.
Responsible agency
St. Mary's County Department of Land Use & Growth Management, Permit Services Division
For a project in or near St. Mary's County, this office is the identified point of contact for permit intake, statutory code enforcement, plan review coordination, and inspection release conditions. Confirm the parcel’s boundary and project type before relying on the county lane.
Direct contact
301-475-4200 ext. 1500 (Permit Services); 301-475-4200 ext. 1580 (Inspections); 301-475-4670 (lot grading/drainage)
Call before mobilizing if the project has a boundary, occupancy, fire, septic, or utility question.
Permit counter
23150 Leonard Hall Drive, Leonardtown, MD 20650
Operating hours
Office Monday-Friday, 8:00 a.m.-5:00 p.m.; permit applications accepted Monday and Thursday 8:30 a.m.-2:00 p.m. and Tuesday, Wednesday, and Friday 8:30 a.m.-4:30 p.m.
Review expectation
N/A - the county publishes permit-counter hours and electronic status tracking but no single standard plan-review timeline. Inspection-request submissions are expected to receive a response within 48 hours.
Compliance workbench
Choose the next project decision.
Apply online
Open the verified digital gateway, application form, and review timeline.
Open guide →Fees & penalties
Understand fee schedules, enforcement exposure, and stop-work liabilities.
Open guide →Codes & exemptions
Read the code framework, minor-work exemptions, and inspection lane.
Open guide →Agency website
Visit the primary public source for current notices and contact changes.
Open guide →Source trail
Official sources for this profile
Use these direct agency or licensing links to confirm current instructions before you file, pay, or schedule work. External pages control if their information differs from this directory.
Project questions
Frequently asked questions for St. Mary's County
Who handles permitting for this jurisdiction?
St. Mary's County Department of Land Use & Growth Management, Permit Services Division is the identified county-level authority for this profile. Confirm that the property is in its service area before filing.
How should I begin an application?
Begin with the online permit gateway listed in the application guide. If the portal does not recognize the address or project type, contact 301-475-4200 ext. 1500 (Permit Services); 301-475-4200 ext. 1580 (Inspections); 301-475-4670 (lot grading/drainage).
How long might review take?
N/A - the county publishes permit-counter hours and electronic status tracking but no single standard plan-review timeline. Inspection-request submissions are expected to receive a response within 48 hours.
How are inspections scheduled?
Use the county's permit status system for application tracking. County construction/site inspections can be requested through the online Inspection Request Form; requests are normally answered within 48 hours. For an immediate health or safety threat call DPW&T at 301-475-4200 ext. 3531. Building, electrical, mechanical, plumbing, and fire inspection requirements vary by permit and must be completed before the Certificate of Occupancy; inspections also verify zoning, stormwater, critical-area, and forest-conservation compliance.
Which codes and exemptions should I review?
The 2024 St. Mary's County Building Code incorporates the 2021 International Building Code, 2021 International Residential Code, 2021 International Energy Conservation Code, 2021 International Existing Building Code, and 2021 International Swimming Pool and Spa Code, with county and Maryland amendments. It also references the Maryland State Plumbing Code and 2018 International Fuel Gas and Mechanical Codes as applicable under the ordinance. All new permit applications are reviewed under the 2026 National Electrical Code beginning July 1, 2026. The county code exempts one-story detached tool/storage sheds, playhouses, or similar non-habitable accessory structures no larger than 120 square feet when outside the floodplain; fences no higher than 7 feet; retaining walls no higher than 4 feet unless supporting a surcharge or certain liquids; certain grade-level sidewalks and driveways; painting, papering, tiling, carpeting, cabinets, countertops, and similar finish work; and some tanks and temporary stage sets. Exemption does not authorize work that violates other laws or ordinances, and a garage or carport still needs a permit even if under 600 square feet, although it may be exempt from building-code inspections.