Middlesex County, Massachusetts Interactive ZIP Code Map

Overview of Middlesex County ZIP Codes

Middlesex County, Massachusetts, the most populous county in New England, features a dense and varied ZIP Code system covering historic industrial cities, affluent suburbs, and major academic hubs like Cambridge and Somerville. The county includes 118 total ZIP Codes, comprised of standard residential delivery areas, dedicated PO Box facilities, and unique codes for institutions like Harvard University and Hanscom AFB.

• Total ZIP Codes: 118
• Standard residential ZIP Codes: 93
• PO Box ZIP Codes: 18
• Unique / business ZIP Codes: 7 (e.g., Harvard Univ, Raytheon)
• Census ZIP Code Tabulation Areas (ZCTAs): 93

ZIP Code Range in Middlesex County

Middlesex County ZIP Codes fall within the "014", "017", "018", "021", and "024" prefixes:

• Lowest ZIP Code: 01431 (Ashby)
• Highest ZIP Code: 02495 (Newton - Nonantum)
• Overall ZIP range: 01431–02495

Post Offices and PO Box ZIP Codes

• PO Box ZIP Codes: 18 PO Box-only ZIP Codes (e.g., 01703, 01705, 01813)
• Post office facilities: 84 USPS post offices, stations, and branches throughout the county
• PO Box locations: Concentrated in urban centers like Framingham and major suburban hubs

Cities, Towns, and Communities Covered by Middlesex County ZIP Codes

Middlesex County encompasses 54 cities and towns, ranging from major urban areas to historic suburbs and college towns.

Major Cities and Municipalities

• Cambridge
• Lowell
• Newton
• Framingham
• Woburn
• Medford
• Malden
• Somerville
• Waltham
• Marlborough

Additional Towns and Communities

• Arlington, Bedford, Billerica, Burlington, Chelmsford
• Dracut, Hudson, Lincoln, Lexington, Tewksbury, Wilmington
• Sudbury, Stoneham, Wakefield, Winchester, Weston
• Ashby, Ayer, Groton, Pepperell (Northern Middlesex)

ZIP Codes often cross municipal boundaries; for example, 02135 is technically Boston (Suffolk County) but borders Brighton/Newton, while 01701 covers parts of Framingham and Ashland.

ZIP Code Population Patterns

Middlesex County ZIP Codes show a mix of high-density urban ZIPs and less dense suburban and rural ZIP polygons.

• Most populated ZIP Code areas: Malden's 02148 is the most populous, exceeding 66,000 residents, followed by Medford (02155) and Lowell (01852).
• Least populated ZIP Codes: Rural outposts like 01474 (Townsend) and unique codes like 02163 (Harvard Business School) have smaller residential populations.

Middlesex County has a population of over 1.6 million, making it the most populous county in Massachusetts and the 22nd most populous in the United States.

Key ZIP Code Statistics (Summary)