Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — STATE/MD/COUNTY/FREDERICK

Frederick County, MD ZIP codes

There are 32 ZIP codes in Frederick County, MD, in 27 towns, from 21701 to 21798. The largest are 21702 (Frederick), 21703 (Frederick) and 21701 (Frederick).

The county seat is Frederick.

ZIP codes
32
Towns
27
County seat
Frederick
County FIPS
24021
Population
287,048
Median household income
$122,002
Land area
661 sq mi
Area codes
227, 240, 301

Frederick County ZIP codes by town

Frederick (county seat)
21701, 21702, 21703, 21704, 21705, 21709

Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.

Map of Frederick County ZIP codes

2170121702217032170421705217092171021714217162171721718217272175421755217582175921762217692177021771217732177421775217772177821780217882179021791217922179321798

The ZIP codes of Frederick County, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Frederick County in numbers

About 287,048 people live in Frederick County, in 104,635 households, the 7th most populous of Maryland's 24 counties. The median household income is $122,002 a year, 18% above the Maryland median of $103,678 (US: $80,734). The median owner-occupied home is valued at $464,600 (11% above the Maryland median), and median gross rent is $1,774 a month. The median age is 39.0; 45.8% of adults 25 and over hold a bachelor's degree or higher (43.4% across Maryland); the average commute takes 33 minutes.

Population287,048Frederick287,048
Households104,635Frederick104,635
Median age39.0Frederick39.0Maryland39.4US 38.9
Median household income$122,002Frederick$122,002Maryland$103,678US $80,734
Median home value$464,600Frederick$464,600Maryland$419,900US $332,700
Median gross rent$1,774Frederick$1,774Maryland$1,705US $1,413
Bachelor's degree or higher45.8%Frederick45.8%Maryland43.4%US 35.7%
Mean commute33.1 minFrederick33.1 minMaryland31.1 minUS 26.4 min
Population density435 / sq miFrederick435 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates. Survey estimates carry margins of error, wider for small places. Sources and methods.

Largest towns in Frederick County

Largest towns in Frederick County
TownZIP codesPopulation
Frederick 6 83,395
Mount Airy 1 9,805
Brunswick 1 8,450
Ijamsville 1 8,156
Walkersville 1 6,414
Thurmont 1 6,254
Middletown 1 5,014
Knoxville 1 4,409
Monrovia 1 3,568
Jefferson 1 3,314
Braddock Heights 1 2,892
Emmitsburg 1 2,845
Point Of Rocks 1 2,462
Myersville 1 2,358
Adamstown 1 2,025

Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.

Neighbouring counties

Counties that share a ZIP code with Frederick County.

Not sure you are in Frederick County? What county am I in? answers from your location, near a county line included.

Every ZIP code in Frederick County, with figures

ZIP codes in Frederick County
ZIP City Type Population Median income Median home
21701 Frederick , MD Standard 43,048 $106,577 $435,000
21702 Frederick , MD Standard 49,605 $106,983 $426,300
21703 Frederick , MD Standard 41,960 $106,334 $384,600
21704 Frederick , MD Standard 20,006 $161,063 $612,000
21705 Frederick , MD Standard 6 — —
21709 Frederick , MD No street area — — —
21710 Adamstown , MD Standard 4,661 $163,864 $591,100
21714 Braddock Heights , MD Standard 95 $161,806 $415,600
21716 Brunswick , MD Standard 7,200 $109,382 $361,300
21717 Buckeystown , MD Standard 245 $158,413 $430,600
21718 Burkittsville , MD Standard 134 $93,500 $576,400
21727 Emmitsburg , MD Standard 6,052 $95,236 $331,100
21754 Ijamsville , MD Standard 8,156 $182,188 $647,300
21755 Jefferson , MD Standard 5,909 $137,417 $529,600
21758 Knoxville , MD Standard 4,409 $111,528 $424,600
21759 Ladiesburg , MD No street area — — —
21762 Libertytown , MD Standard 139 — —
21769 Middletown , MD Standard 11,965 $151,563 $507,000
21770 Monrovia , MD Standard 8,751 $183,571 $632,500
21771 Mount Airy , MD Standard 33,031 $157,302 $556,200
21773 Myersville , MD Standard 5,826 $161,908 $544,400
21774 New Market , MD Standard 17,134 $171,103 $541,000
21775 New Midway , MD No street area — — —
21777 Point Of Rocks , MD Standard 2,462 $159,708 $480,500
21778 Rocky Ridge , MD Standard 745 $76,458 $382,100
21780 Sabillasville , MD Standard 2,159 $83,785 $451,600
21788 Thurmont , MD Standard 11,654 $98,856 $379,200
21790 Tuscarora , MD Standard 170 $77,656 —
21791 Union Bridge , MD Standard 5,340 $93,015 $379,800
21792 Unionville , MD No street area — — —
21793 Walkersville , MD Standard 10,719 $121,971 $459,400
21798 Woodsboro , MD Standard 2,928 $116,607 $498,400

Cite this page

zipcodes.pro. “Frederick County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/md/county/frederick

Underlying data is public domain or openly licensed — sources, vintages and licences.