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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 — ZIP/20621

20621

ZIP 20621 is Chaptico, Maryland, in St. Mary's County; area codes 240, 301 and 227; Eastern time.

Type
Standard
Time zone
America/New_York
County
St. Mary's
Metro area
Lexington Park, MD
Population
958
Coordinates
38.3261, -76.8011
☼ Live from 20621 — Chaptico, MD

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Local time: —

Where 20621 is

Approximate ZIP boundary (Census ZCTA 2020). ZIP codes are mail routes, not areas, so the shape shown is the Census tabulation area that approximates it.

★ Weird and wonderful facts about 20621
  • 🔢 Type 20621 into a pocket calculator and turn it upside down: IZgOZ — not quite a word, sorry.
  • ➕ As a number, 20,621 = 17 × 1213. Its digits add up to 11, a total 714 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101000010001101
  • 🏠 Its numerical neighbours: 20620 (Callaway, MD, 16 mi away) and 20622 (Charlotte Hall, MD, 8 mi away).
  • 🔄 Backwards, 20621 becomes 12602 — and that is a real ZIP code: Poughkeepsie, NY, 287 miles away.
  • 👥 27 other ZIP codes are made of exactly the same digits (01226, 01262, 02126, 12062, 12206, 12260, …). The farthest-flung twin is 62201 in East Saint Louis, IL, 721 miles away.
  • 🧭 Farther south than 56% of all ZIP codes, and farther east than 82%.
  • 🎯1,170 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 20621 and you would come out at 38.33°S, 103.20°E — 839 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 50m of daylight. Shortest: 9h 29m.
  • 📏 At 13.9 square miles of land, 20621 is bigger than 32% of ZIP codes — room for about 11 Central Parks.
🌙 The sky over 20621 today
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🌋 Shake report
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Source: USGS.

People and housing

Population958This ZIP958
Households534This ZIP534
Housing units611This ZIP611
Median age63.0This ZIP63.0Maryland39.4US 38.9
Median home value$481,100This ZIP$481,100Maryland$419,900US $332,700
Bachelor's degree or higher15.8%This ZIP15.8%
Mean commute45.3 minThis ZIP45.3 min
Population density69.1 / sq miThis ZIP69.1 / sq mi

Business and tax activity

Business establishments14This ZIP14
Employees88This ZIP88
Annual payroll$2,574,000This ZIP$2,574,000
Tax returns filed720This ZIP720
Total adjusted gross income$61,936,000This ZIP$61,936,000

Land area

Land area13.86 sq miThis ZIP13.86 sq mi
Water area0.11 sq miThis ZIP0.11 sq mi

ZIP codes near 20621

ZIPCityDistance
20618 Bushwood, MD 3.5 mi
20624 Clements, MD 3.8 mi
20682 Rock Point, MD 3.9 mi
20609 Avenue, MD 4.2 mi
20661 Mount Victoria, MD 5.0 mi
20625 Cobb Island, MD 5.3 mi
20606 Abell, MD 5.7 mi
20660 Morganza, MD 5.9 mi
20664 Newburg, MD 6.0 mi
20627 Compton, MD 6.3 mi

Find every ZIP code within 10 miles of 20621 →

Questions about this ZIP code

Where is ZIP code 20621?

20621 is in Chaptico, Maryland, in St. Mary's County, part of the Lexington Park, MD metropolitan area. Its published point location is 38.3261, -76.8011.

What county is 20621 in?

20621 lies in St. Mary's County.

What area code is 20621?

Chaptico uses area codes 240, 301 and 227, from NANPA's telephone records.

What time zone is 20621 in?

20621 uses America/New_York.

How many people live in 20621?

About 958 people live in ZIP code 20621, in 534 households, at 69.1 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.

What ZIP codes are near 20621?

The closest are 20618 (3.5 mi), 20624 (3.8 mi), 20682 (3.9 mi), 20609 (4.2 mi) and 20661 (5 mi).

Is 20621 a PO Box ZIP code?

20621 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “20621 ZIP Code — Chaptico, Maryland (St. Mary's County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/20621

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