When was Frederick County founded?

Frederick County was founded in 1748, formed from Prince Georges County, and named after Frederick Calvert, 6th Baron Baltimore and Frederick, Prince of Wales.

What is the county seat of Frederick County?

The county seat of Frederick County is Frederick.

Is there an online parcel map for Frederick County?

Yes. Frederick County publishes a parcel map of 129,325 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Frederick County's boundary or name changed?

Frederick County was created in 1748 from Prince Georges County. Since then the Atlas of Historical County Boundaries records 3 later changes, chiefly involving Baltimore County, Carroll County and Montgomery County.

Who issues building permits in Frederick County?

The county's page on building permits: Current Permits. Inside a city or town, ask that city first.

Who issues septic and well permits in Frederick County?

The county's page on septic systems and wells: Health Services Division.

Is my lot in a flood zone?

We do not have flood maps for Frederick County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 24021

Frederick CountyMaryland

Frederick County, Maryland was created in 1748 from Prince Georges County and is seated in Frederick.

Founded1748
County seatFrederick
Named forFrederick Calvert, 6th Baron Baltimore and Frederick, Prince of Wales
Land area661 sq mi + 6.8 sq mi water
Population271,717 2020 Census
Parcels mapped129,325 checked 16 October 2026

Open the free map Click any parcel in Frederick County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 19 October 2026

Census outline · seat marked

History

Formed in 1748 from Prince Georges County

An old deed may name a county that no longer exists, or a boundary that has since moved.

Frederick County was created on December 10, 1748, from Prince Georges County and Non-County Area 1, and gained territory from Baltimore County two years later. The county lost land in 1776 to the creation of Montgomery and Washington counties, and again in 1836 when Carroll County was formed.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1748
Frederick County created Frederick created from Prince Georges and Non-County Area 1.
from Prince Georges
10 December 1748 · Archives of Md., 46:141-142
1750
Gained territory Frederick gained from Baltimore.
from Baltimore
2 June 1750 · Archives of Md., 46:468
1776
Lost territory Frederick lost to creation of Montgomery and Washington.
to Montgomery to Washington
2 October 1776 · Md., Laws Since 1763, "Proceedings of Convention," 6 Sep. 1776
1836
Lost territory Frederick lost to creation of Carroll.
to Carroll
19 January 1836 · Md. Laws 1835, ch. 256, sec. 1; Md. Laws 1836, ch. 19

Land and parcels

What the maps cover in Frederick

Who publishes each layer, how good it is, and when we last checked.

Parcels Good enough

Lot lines and tax-map numbers for 129,325 parcels from Frederick County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 16 October 2026
Address points Missing

No public address points layer found for Frederick County yet.
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Frederick by the Census

Population

271,717 2020 Census count

Housing units

103,493 2020 Census count

Land area

661 square miles

Water area

6.8 square miles

People per sq mi

411 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Who to ask before you build, dig or sell

Official county pages only. We link to them; we do not copy them, because they change.

Inside a city or town, permits usually come from that city rather than the county.

Records

Assessor and property recordsfrom frederickcountymd.gov · checked 13 October 2026
Clerk of court: deeds and plats
Circuit Court
from frederickcountymd.gov · checked 13 October 2026

Permits

Health department: septic and well
Health Services Division
from frederickcountymd.gov · checked 13 October 2026
Current Permitsfrom planningandpermitting.frederickcountymd.gov
Electrical Permitsfrom frederickcountymd.gov

Zoning and code

Planning and zoningfrom frederickcountymd.gov · checked 13 October 2026
Amendments to Gaming Ordinancefrom frederickcountymd.gov
Regulations and Ordinancesfrom frederickcountymd.gov
Zoningfrom frederickcountymd.gov
Zoning Administrationfrom frederickcountymd.gov

County government

County government
The official website of Frederick County.
frederickcountymd.gov

See your own lot on these maps

Open Frederick County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Frederick County

When was Frederick County founded?: Frederick County was founded in 1748, formed from Prince Georges County, and named after Frederick Calvert, 6th Baron Baltimore and Frederick, Prince of Wales.
What is the county seat of Frederick County?: The county seat of Frederick County is Frederick.
Is there an online parcel map for Frederick County?: Yes. Frederick County publishes a parcel map of 129,325 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Frederick County's boundary or name changed?: Frederick County was created in 1748 from Prince Georges County. Since then the Atlas of Historical County Boundaries records 3 later changes, chiefly involving Baltimore County, Carroll County and Montgomery County.
Who issues building permits in Frederick County?: The county's page on building permits: Current Permits. Inside a city or town, ask that city first.
Who issues septic and well permits in Frederick County?: The county's page on septic systems and wells: Health Services Division.
Is my lot in a flood zone?: We do not have flood maps for Frederick County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

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