County ZIP codes · Wisconsin · FIPS 55139
Winnebago County, WI ZIP Codes
Winnebago County, Wisconsin has 22 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 18 residential and 4 for PO boxes or a single organization. 11 of the residential ones lie mainly in Winnebago County and 7 mainly in a neighboring county; 9 cross the county line. Median household income ranges from $61,794 in 54901 (Oshkosh) to $109,868 in 54979 (Van Dyne) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of Winnebago County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are its ZIP codes?
The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $66,699 and $90,813.
They carry 15 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 18 residential ZIP codes in Winnebago County
11 ZIP codes lie mainly in Winnebago County; 7 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 54956 | Neenah | 46,567 | 755 | $86k | $257k | 96% |
| 54901 | Oshkosh | 37,294 | 2,241 | $62k | $178k | 100% |
| 54904 | Oshkosh | 22,273 | 286 | $93k | $281k | 99% |
| 54902 | Oshkosh | 22,243 | 635 | $66k | $171k | 100% |
| 54963 | Omro | 7,271 | 96 | $86k | $238k | 100% |
| 54986 | Winneconne | 5,394 | 186 | $93k | $301k | 99% |
| 54947 | Larsen | 2,323 | 50 | $91k | $280k | 100% |
| 54964 | Pickett | 974 | 28 | $83k | $268k | 72% |
| 54927 | Butte Des Morts | 540 | 2,477 | $129k | $244k | 100% |
| 54985 | Winnebago | 249 | 2,767 | – | – | 100% |
| 54980 | Waukau | 218 | 625 | $32k | $190k | 100% |
Partly in Winnebago County
| In this county | ||||||
|---|---|---|---|---|---|---|
| 54940 | Fremont | 4,533 | 50 | $91k | $307k | 30% |
| 54952 | Menasha | 27,312 | 973 | $69k | $213k | 23% |
| 54971 | Ripon | 10,907 | 98 | $67k | $193k | 20% |
| 54923 | Berlin | 8,793 | 65 | $66k | $189k | 8% |
| 54915 | Appleton | 44,367 | 2,950 | $87k | $270k | 6% |
| 54979 | Van Dyne | 2,037 | 77 | $110k | $295k | 4% |
| 54914 | Appleton | 31,849 | 1,657 | $80k | $237k | 4% |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
11 ZIP codes of Winnebago County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Winnebago | Elsewhere |
|---|---|---|
| 54956 | 96% | Outagamie County 4% |
| 54915 | 6% | Calumet County 50%; Outagamie County 44% |
| 54914 | 4% | Outagamie County 96% |
| 54952 | 23% | Calumet County 77% |
| 54904 | 99% | |
| 54971 | 20% | Fond du Lac County 59%; Green Lake County 21% |
| 54923 | 8% | Waushara County 48%; Green Lake County 43% |
| 54986 | 99% | |
| 54940 | 30% | Waushara County 31%; Waupaca County 30%; Outagamie County 10% |
| 54979 | 4% | Fond du Lac County 96% |
| 54964 | 72% | Fond du Lac County 28% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
PO Box and single-organization ZIP codes
Source: GeoNames postal codes (CC BY 4.0).
Which first three digits do Winnebago County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Winnebago County starts with 549.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 549 | Milwaukee, WI (SCF 530) | 22 | 66 |
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.