ZIP codes in Calvert County
15 ZIPs touch Calvert County, Maryland. The blue dashed line is the county border; orange ZIPs reach into it.
15
ZIP codes
4
cross the county line
97,254
people in these ZIPs
24
counties in MD
Most people
Calvert County ZIP list
More counties in Maryland
- Allegany County22
- Anne Arundel County48
- Baltimore County66
- Baltimore city50
- Caroline County11
- Carroll County16
- Cecil County17
- Charles County28
- Dorchester County18
- Frederick County39
Questions people actually ask
How many ZIP codes are in Calvert County, Maryland?
15 ZIP codes reach into Calvert County, including 1 PO Box or single-address ZIPs placed by the town they serve. 4 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Calvert County has the most people?
20657 (Lusby) has about 20,699 residents, the most of any ZIP touching Calvert County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Calvert County and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in Calvert County. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
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Updated 2026-11-10 · Where the data comes from