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U.S. ZIP Codes Database 2026

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ZIP Code Details for Rock

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

Postal Information

ZIP Code 20847
Type Po Box
Primary City Rockville
State MD
County Montgomery County
Acceptable Cities -
Unacceptable -
Time Zone America/New_York
Area Codes 240
Latitude 39,08° N
Longitude -77,15° 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 Rockville, MD

Postal Information

ZIP Code 20848
Type Po Box
Primary City Rockville
State MD
County Montgomery County
Acceptable Cities -
Unacceptable -
Time Zone America/New_York
Area Codes 240
Latitude 39,08° N
Longitude -77,15° 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 Rockville, MD

Postal Information

ZIP Code 20849
Type Po Box
Primary City Rockville
State MD
County Montgomery County
Acceptable Cities -
Unacceptable -
Time Zone America/New_York
Area Codes 240
Latitude 39,08° N
Longitude -77,15° 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 Rockville, MD

Postal Information

ZIP Code 20850
Type Standard
Primary City Rockville
State MD
County Montgomery County
Acceptable Cities Potomac
Unacceptable -
Time Zone America/New_York
Area Codes 227, 240, 301
Latitude 39,08° N
Longitude -77,15° 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 Rockville, MD

Postal Information

ZIP Code 20851
Type Standard
Primary City Rockville
State MD
County Montgomery County
Acceptable Cities -
Unacceptable -
Time Zone America/New_York
Area Codes 227, 240, 301
Latitude 39,08° N
Longitude -77,12° 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 Rockville, MD

Postal Information

ZIP Code 20852
Type Standard
Primary City Rockville
State MD
County Montgomery County
Acceptable Cities N Bethesda, North Bethesda
Unacceptable No Bethesda
Time Zone America/New_York
Area Codes 227, 240, 301
Latitude 39,05° N
Longitude -77,12° 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 Rockville, MD

Postal Information

ZIP Code 20853
Type Standard
Primary City Rockville
State MD
County Montgomery County
Acceptable Cities -
Unacceptable -
Time Zone America/New_York
Area Codes 227, 240, 301
Latitude 39,1° N
Longitude -77,09° 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 Rockville, MD

Postal Information

ZIP Code 20857
Type Unique
Primary City Rockville
State MD
County Montgomery County
Acceptable Cities -
Unacceptable Hhs
Time Zone America/New_York
Area Codes 240
Latitude 39,08° N
Longitude -77,15° 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 Rockville, MD

Postal Information

ZIP Code 21661
Type Standard
Primary City Rock Hall
State MD
County Kent County
Acceptable Cities -
Unacceptable -
Time Zone America/New_York
Area Codes 410, 443, 667
Latitude 39,14° N
Longitude -76,24° 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 Rock Hall, MD

Postal Information

ZIP Code 21777
Type Standard
Primary City Point Of Rocks
State MD
County Frederick County
Acceptable Cities Pt Of Rocks
Unacceptable -
Time Zone America/New_York
Area Codes 227, 240, 301
Latitude 39,28° N
Longitude -77,53° 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 Point Of Rocks, MD

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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.