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 — RANKINGS/MD/SMALLEST-AREA

Smallest ZIP Codes in Maryland by Land Area

What this measures. Land area of the Census tabulation area, smallest first. These are almost always dense urban ZIP codes covering a few city blocks. Source: Census Gazetteer, data release 2026-10-12.

# ZIP City County Land area
1 21287 Baltimore Baltimore city 0.00 sq mi
2 20661 Mount Victoria Charles 0.01 sq mi
3 21542 Midland Allegany 0.02 sq mi
4 21705 Frederick Frederick 0.02 sq mi
5 21233 Baltimore Baltimore city 0.03 sq mi
6 21105 Maryland Line Baltimore 0.09 sq mi
7 20899 Gaithersburg Montgomery 0.11 sq mi
8 20892 Bethesda Montgomery 0.12 sq mi
9 21251 Baltimore Baltimore city 0.12 sq mi
10 21866 Tylerton Somerset 0.12 sq mi
11 20894 Bethesda Montgomery 0.13 sq mi
12 21641 Hillsboro Caroline 0.14 sq mi
13 20812 Glen Echo Montgomery 0.18 sq mi
14 21285 Towson Baltimore 0.18 sq mi
15 21653 Newcomb Talbot 0.19 sq mi
16 20612 Benedict Charles 0.23 sq mi
17 21867 Upper Fairmount Somerset 0.24 sq mi
18 21781 Saint James Washington 0.24 sq mi
19 21250 Baltimore Baltimore 0.25 sq mi
20 21715 Brownsville Washington 0.25 sq mi
21 21252 Towson Baltimore 0.25 sq mi
22 21746 Hagerstown Washington 0.26 sq mi
23 21540 Luke Allegany 0.27 sq mi
24 20686 Saint Marys City St. Mary's 0.27 sq mi
25 21664 Secretary Dorchester 0.29 sq mi
26 20742 College Park Prince George's 0.32 sq mi
27 21718 Burkittsville Frederick 0.33 sq mi
28 20880 Washington Grove Montgomery 0.33 sq mi
29 20896 Garrett Park Montgomery 0.34 sq mi
30 21767 Maugansville Washington 0.34 sq mi
31 21890 Westover Somerset 0.35 sq mi
32 20889 Bethesda Montgomery 0.39 sq mi
33 21051 Fork Baltimore 0.40 sq mi
34 21052 Fort Howard Baltimore 0.40 sq mi
35 21077 Harmans Anne Arundel 0.44 sq mi
36 21714 Braddock Heights Frederick 0.45 sq mi
37 21762 Libertytown Frederick 0.45 sq mi
38 20765 Galesville Anne Arundel 0.47 sq mi
39 21810 Allen Wicomico 0.48 sq mi
40 21734 Funkstown Washington 0.48 sq mi
41 20625 Cobb Island Charles 0.49 sq mi
42 21652 Neavitt Talbot 0.52 sq mi
43 21130 Perryman Harford 0.55 sq mi
44 21560 Spring Gap Allegany 0.56 sq mi
45 20656 Loveville St. Mary's 0.58 sq mi
46 21717 Buckeystown Frederick 0.61 sq mi
47 20615 Broomes Island Calvert 0.73 sq mi
48 20712 Mount Rainier Prince George's 0.73 sq mi
49 21914 Charlestown Cecil 0.73 sq mi
50 21930 Georgetown Cecil 0.74 sq mi

Showing the top 50 of 477 ZIP codes in Maryland that have this figure and meet the threshold above. 21287 ranks 1st at 0.00 sq mi, against 0.74 sq mi in 50th place.

Other rankings for Maryland

Cite this page

zipcodes.pro. “Smallest ZIP Codes in Maryland by Land Area.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/md/smallest-area

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