Find the last 4 digits (ZIP+4) for an address in 21771

ZIP 21771, Mount Airy, MD is filled in. Just type the street address.

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ZIP Code 21771 – Mount Airy, MD

Mount Airy, Maryland · Frederick County · Eastern time

ZIP code21771
CityMount Airy
StateMaryland
CountyFrederick CountyCarroll CountyHoward CountyMontgomery County
Population33,031
Time zoneEastern · local time
ZIP typeStandard (has a Census ZCTA area)
Land area89.52 sq mi
Center (lat, long)39.3949, -77.1582

Area codes in this area

227240301

These are the area codes that most often serve ZIP 21771 (including overlays). The exact area code depends on the phone number — landlines, mobiles and overlays can differ even on the same street.

Map

Nearby ZIP codes

21792 Unionville · 5.7 mi21765 Lisbon · 6.1 mi21770 Monrovia · 6.1 mi21774 New Market · 6.3 mi21797 Woodbine · 6.5 mi20872 Damascus · 7.1 mi21762 Libertytown · 7.6 mi21776 New Windsor · 9 mi

About ZIP 21771

ZIP code 21771 is assigned to Mount Airy, Maryland. It crosses 4 counties; most of its land is in Frederick County. Its Census area covers about 89.52 square miles of land. The closest neighboring ZIP is 21792 (Unionville), about 5.7 miles away.

Every address in 21771 also has a 4-digit add-on code (ZIP+4) that points to a smaller delivery area. Use the box above to find it.

Sources: US Census Bureau (ZCTA, county relationship files), GeoNames (CC BY 4.0), NANPA via NumberResearch.org (CC BY 4.0). Map © OpenStreetMap contributors. ZIP areas are approximate. Population: U.S. Census Bureau, ACS 5-year estimates, 2024 (ZCTA). Data sources