ZIP codes in Nassau County
90 ZIPs touch Nassau County, New York. The blue dashed line is the county border; orange ZIPs reach into it.
90
ZIP codes
3
cross the county line
1,401,387
people in these ZIPs
62
counties in NY
Most people
Nassau County ZIP list
More counties in New York
- Kings County55
- Lewis County23
- Livingston County33
- Madison County33
- Monroe County69
- Montgomery County21
- New York County147
- Niagara County25
- Oneida County65
- Onondaga County71
- Ontario County31
- Orange County58
Questions people actually ask
How many ZIP codes are in Nassau County, New York?
90 ZIP codes reach into Nassau County, including 20 PO Box or single-address ZIPs placed by the town they serve. 3 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Nassau County has the most people?
11550 (Hempstead) has about 60,960 residents, the most of any ZIP touching Nassau County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Nassau 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 Nassau 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