County ZIP codes · Washington · FIPS 53075
Whitman County, WA ZIP Codes
Whitman County, Washington has 24 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 22 residential and 2 for PO boxes or a single organization. 20 of the residential ones lie mainly in Whitman County and 2 mainly in a neighboring county; 6 cross the county line. Median household income ranges from $48,231 in 99163 (Pullman) to $87,464 in 99161 (Palouse) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of Whitman 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 $64,699 and $73,393.
They carry 22 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 22 residential ZIP codes in Whitman County
20 ZIP codes lie mainly in Whitman County; 2 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 99163 | Pullman | 34,022 | 161 | $48k | $436k | 100% |
| 99111 | Colfax | 4,038 | 13 | $73k | $296k | 100% |
| 99161 | Palouse | 1,435 | 19 | $88k | $303k | 100% |
| 99170 | Rosalia | 926 | 5 | $59k | $238k | 57% |
| 99171 | Saint John | 895 | 4 | $53k | $221k | 100% |
| 99033 | Tekoa | 832 | 21 | $59k | $253k | 82% |
| 99130 | Garfield | 693 | 9 | $82k | $232k | 100% |
| 99179 | Uniontown | 645 | 10 | $79k | $398k | 100% |
| 99125 | Endicott | 611 | 3 | $53k | $196k | 100% |
| 99143 | Lacrosse | 585 | 2 | $38k | $124k | 100% |
| 99158 | Oakesdale | 561 | 6 | $78k | $302k | 100% |
| 99113 | Colton | 560 | 6 | $105k | $398k | 100% |
| 99102 | Albion | 495 | 1,452 | $57k | $231k | 100% |
| 99128 | Farmington | 259 | 4 | $59k | $364k | 93% |
| 99017 | Lamont | 230 | 3 | $59k | $121k | 100% |
| 99176 | Thornton | 163 | 3 | $128k | $283k | 100% |
| 99333 | Hooper | 151 | 2 | $98k | $450k | 89% |
| 99149 | Malden | 100 | 52 | $26k | $50k | 100% |
| 99174 | Steptoe | 69 | 2,556 | $50k | $255k | 100% |
| 99136 | Hay | 14 | 1 | $88k | – | 100% |
Partly in Whitman County
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?
6 ZIP codes of Whitman County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Whitman | Elsewhere |
|---|---|---|
| 99004 | 4% | Spokane County 96% |
| 99347 | 2% | Garfield County 89%; Columbia County 10% |
| 99170 | 57% | Spokane County 43% |
| 99033 | 82% | Spokane County 16%; Benewah County 2% |
| 99128 | 93% | Latah County 7% |
| 99333 | 89% | Adams County 11% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
PO Box and single-organization ZIP codes
| ZIP | Postal name |
|---|---|
| 99104 | Belmont |
| 99164 | Pullman |
Source: GeoNames postal codes (CC BY 4.0).
Which first three digits do Whitman County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Whitman County's ZIP codes use 3 prefixes: 990, 991 and 993.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 990 | Spokane, WA (SCF 990) | 3 | 32 |
| 991 | Spokane, WA (SCF 990) | 19 | 67 |
| 993 | Spokane, WA (SCF 990) | 2 | 36 |
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.