City ZIP codes · Colorado
Boulder, CO ZIP Codes
11 ZIP codes use the postal name Boulder, Colorado (Census 2020 ZCTAs and GeoNames postal codes, October 2026): 6 residential and 5 for PO boxes or a single organization. Median household income runs from $61,698 in 80302 to $126,558 in 80304, 2.1 times as much (Census Bureau, ACS 2020-2024). Boulder's most populous ZIP code is 80302, with 29,569 people (ACS 2020-2024); 5% of its land is in the city of Boulder.
- ACS2020-24
- Census2020
- GeoNames2026
Where are Boulder's ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are Boulder's ZIP codes?
The highest median household income is in 80304 ($126,558), the lowest in 80302 ($61,698). Home values run from $793,200 in 80301 to $1,210,200 in 80304.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013, B25077, B01003).
All 6 residential ZIP codes of Boulder
| County | |||||
|---|---|---|---|---|---|
| 80302 | Boulder County | 29,569 | 315 | $62k | $1.19M |
| 80304 | Boulder County | 25,383 | 2,812 | $127k | $1.21M |
| 80301 | Boulder County | 25,007 | 873 | $95k | $793k |
| 80303 | Boulder County | 24,996 | 1,142 | $79k | $962k |
| 80305 | Boulder County | 16,291 | 2,799 | $126k | $1.03M |
| 80310 | Boulder County | 7,692 | 14,114 | – | – |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; 2023 Gazetteer land areas (2020 ZCTAs); town names from simplemaps US ZIP Codes (CC BY 4.0) and GeoNames (CC BY 4.0).
PO Box and single-organization ZIP codes in Boulder
5 ZIP codes named Boulder have no residential delivery area: post office boxes, or one organization (a large employer, an agency, a university) with its own code. The Census Bureau publishes no figures for them.
| ZIP | County |
|---|---|
| 80306 | Boulder County |
| 80307 | Boulder County |
| 80308 | Boulder County |
| 80309 | Boulder County |
| 80314 | Boulder County |
Source: GeoNames postal codes (CC BY 4.0); a ZIP code with no Census ZCTA has no residential delivery area.
Which counties do Boulder's ZIP codes reach?
Boulder's residential ZIP codes lie in Boulder County.
Which places do Boulder's ZIP codes cover?
A postal name is not a city limit. By the Census Bureau's places, Boulder's residential ZIP codes cover Boulder itself and 14 other places, each listed with the ZIP codes that have at least 5% of their land in it or hold most of the place:
- Altona census-designated 80302
- Crisman census-designated 80302
- Eldorado Springs census-designated 80303
- Gold Hill census-designated 80302
- Gunbarrel census-designated 80301
- Lazy Acres census-designated 80302
- Mountain Meadows census-designated 80302
- Paragon Estates census-designated 80303
- Pine Brook Hill census-designated 80304
- Seven Hills census-designated 80302
- Sugarloaf census-designated 80302
- Sunshine census-designated 80302
- Tall Timber census-designated 80302
- Valmont census-designated 80301
Source: U.S. Census Bureau, 2020 ZCTA-to-place relationship file (shares of land).
Which first three digits do Boulder'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 Boulder starts with 803.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 803 | Denver, CO (SCF 800) | 11 | 11 |
All 11 ZIP codes that start with 803 are Boulder's: 6 residential codes and 5 PO Box or unique codes, sorted at Denver, CO (SCF 800).
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.