ZIP codes in Tompkins County
21 ZIPs touch Tompkins County, New York. The blue dashed line is the county border; orange ZIPs reach into it.
21
ZIP codes
10
cross the county line
143,619
people in these ZIPs
62
counties in NY
Most people
Tompkins County ZIP list
More counties in New York
- Seneca County15
- St. Lawrence County56
- Steuben County41
- Suffolk County116
- Sullivan County63
- Tioga County17
- Ulster County66
- Warren County27
- Washington County30
- Wayne County26
- Westchester County85
- Wyoming County25
Questions people actually ask
How many ZIP codes are in Tompkins County, New York?
21 ZIP codes reach into Tompkins County, including 3 PO Box or single-address ZIPs placed by the town they serve. 10 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Tompkins County has the most people?
14850 (Ithaca) has about 68,610 residents, the most of any ZIP touching Tompkins County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Tompkins 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 Tompkins 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