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U.S. ZIP Codes Database 2026

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ZIP Code Details for Ridge

Detailed geographic and postal record lookup for the city of Ridge.

Postal Information

ZIP Code 21685
Type Unique
Primary City Ridgely
State MD
County Caroline County
Acceptable Cities -
Unacceptable Nationwide Fulfill Systems
Time Zone America/New_York
Area Codes 410
Latitude 38,94° N
Longitude -75,88° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Ridgely, MD

Postal Information

ZIP Code 21686
Type Unique
Primary City Ridgely
State MD
County Caroline County
Acceptable Cities -
Unacceptable Nationwide Fulfill Systems
Time Zone America/New_York
Area Codes 410
Latitude 38,94° N
Longitude -75,88° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Ridgely, MD

Postal Information

ZIP Code 21687
Type Unique
Primary City Ridgely
State MD
County Caroline County
Acceptable Cities -
Unacceptable Nationwide Fulfill Systems
Time Zone America/New_York
Area Codes 410
Latitude 38,94° N
Longitude -75,88° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Ridgely, MD

Postal Information

ZIP Code 21688
Type Unique
Primary City Ridgely
State MD
County Caroline County
Acceptable Cities -
Unacceptable Nationwide Fulfill Systems
Time Zone America/New_York
Area Codes 410
Latitude 38,94° N
Longitude -75,88° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Ridgely, MD

Postal Information

ZIP Code 21778
Type Standard
Primary City Rocky Ridge
State MD
County Frederick County
Acceptable Cities -
Unacceptable -
Time Zone America/New_York
Area Codes 227, 240, 301, 410, 443, 667
Latitude 39,61° N
Longitude -77,33° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Rocky Ridge, MD

Postal Information

ZIP Code 21791
Type Standard
Primary City Union Bridge
State MD
County Carroll County
Acceptable Cities Linwood
Unacceptable -
Time Zone America/New_York
Area Codes 227, 240, 301, 410, 443, 667
Latitude 39,56° N
Longitude -77,17° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Union Bridge, MD

Postal Information

ZIP Code 22191
Type Standard
Primary City Woodbridge
State VA
County Prince William County
Acceptable Cities -
Unacceptable Wdbg
Time Zone America/New_York
Area Codes 227, 240, 301, 571, 703
Latitude 38,63° N
Longitude -77,26° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Woodbridge, VA

Postal Information

ZIP Code 22192
Type Standard
Primary City Woodbridge
State VA
County Prince William County
Acceptable Cities Lake Ridge, Prince William, Prince Wm
Unacceptable -
Time Zone America/New_York
Area Codes 571, 703
Latitude 38,68° N
Longitude -77,31° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Woodbridge, VA

Postal Information

ZIP Code 22193
Type Standard
Primary City Woodbridge
State VA
County Prince William County
Acceptable Cities Dale City
Unacceptable Dalecity
Time Zone America/New_York
Area Codes 571, 703
Latitude 38,64° N
Longitude -77,35° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Woodbridge, VA

Postal Information

ZIP Code 22194
Type Po Box
Primary City Woodbridge
State VA
County Prince William County
Acceptable Cities -
Unacceptable -
Time Zone America/New_York
Area Codes 571
Latitude 38,63° N
Longitude -77,26° W

About U.S. ZIP Codes

U.S. ZIP Codes are 5-digit postal codes introduced in 1963 by the USPS to improve mail sorting efficiency. The first digit represents a broad region, the next two identify a sectional center facility, and the final two help pinpoint a local post office or delivery area.

Geographic Breakdown:

  • 1st Digit: Represents a group of states or a broad national region.
  • 2nd/3rd Digits: Represent a regional area or large city.
  • 4th/5th Digits: Identify specific post offices or delivery zones.

ZIP Codes support physical delivery, routing analytics, geocoding, tax calculations, and location-based research.

Geographic Map of Woodbridge, VA

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Postal context

About U.S. ZIP Codes

ZIP codes are a United States Postal Service system introduced in 1963 to make mail routing more accurate and efficient. The standard format uses five digits, while ZIP+4 adds four more digits for a more precise delivery segment.

ZIP codes cover the United States, its territories, military mail routes, and other USPS delivery points. This directory organizes that data for practical lookup by ZIP code, city, county, and state.