ZIP codes in Baltimore city

50 ZIPs touch Baltimore city, Maryland. The blue dashed line is the county border; orange ZIPs reach into it.

50

ZIP codes

18

cross the county line

996,108

people in these ZIPs

24

counties in MD

Most people

Baltimore city ZIP list

Questions people actually ask

How many ZIP codes are in Baltimore city, Maryland?

50 ZIP codes reach into Baltimore city, including 17 PO Box or single-address ZIPs placed by the town they serve. 18 of them are only partly in the county and also cover a neighboring county.

Which ZIP code in Baltimore city has the most people?

21234 (Parkville) has about 66,334 residents, the most of any ZIP touching Baltimore city, in the Census Bureau’s ACS 2020–2024 estimates.

Can a ZIP code be in Baltimore city 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 Baltimore city. 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.

Updated 2026-11-10 · Where the data comes from