Residential delivery area · Colorado
ZIP Code 81101: Alamosa, CO
ZIP code 81101 uses the postal name Alamosa, Colorado and lies mostly in Alamosa County (94% of its land) with the rest in Conejos County (Census 2020 ZIP-county file). About 16,000 people live there (Census Bureau, ACS 2020-2024). Median household income is $54,844 (Census Bureau, ACS 2020-2024). By Census place, its land lies in Alamosa (2%) and Alamosa East (under 1%); 97% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Alamosa · its only residential ZIP
- County
- Alamosa County (94%); Conejos County (6%)
- Census places
- Alamosa (2%); Alamosa East (under 1%) census-designated place
- Micro area
- Alamosa, CO
- House district
- CO-3 119th Congress
- State
- Colorado
- Time zone
- Mountain
- Land area
- 369.0 sq mi · 42 people per sq mi
- PO Box ZIPs
- 81102 also use the name Alamosa
Where is ZIP code 81101?
81101 centers on 37.469°, -105.853° and covers 369.0 square miles of land plus 0.5 of water. It borders 5 ZIP codes: 81146, 81123, 81144, 81151, 81140.
The map draws ZIP code areas only. For the streets inside 81101, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 81101 compare with the rest of Alamosa County?
| Measure | 81101 | In Alamosa County | In CO |
|---|---|---|---|
| People (ACS 2020-2024) | 15,550 | 1st of 5 | 147th of 527 |
| Median household income | $55k | 2nd of 2 | 259th of 277 |
| Median home value | $240k | 1st of 2 | 280th of 311 |
Its median household income is higher than in 21% of U.S. residential ZIP codes, and it is denser than 39% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 81101?
The 2020 Census counted 15,657 people in 81101; the ACS, which samples households over 2020-2024, estimates 15,550. Its boundary changed between the 2010 and 2020 censuses, so the two counts are not compared.
- People, ACS 2020-2024
- 15,550
- 2020 Census count
- 15,657
- Households
- 6,292
- Median age
- 33.4
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 81101?
Of the 15,550 people the ACS estimates in 81101, 23.8% are under 18 and 14.9% are 65 or older. The largest group by race and Hispanic origin is Hispanic or Latino (50.3%), then White (not Hispanic) (43.2%).
- Under 1823.8%
- 18 to 6461.3%
- 65 and older14.9%
- Hispanic or Latino50.3%
- White, not Hispanic43.2%
- Other or two or more3.6%
- Black, not Hispanic1.9%
- Asian, not Hispanic1.1%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 81101 earn?
Median household income is $54,844 (ACS 2020-2024).
- Median household income
- $54,844
- Income per person
- $29,490
- Below the poverty line
- 18.1%
- Unemployed (of the labor force)
- 3.6%
- Adults 25+ with a bachelor's degree
- 32.4%
- Adjusted gross income per tax return, 2022
- $59,0306,800 returns; wages 70% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 81101?
FHFA's house price index for 81101, built from repeat sales and appraisals of the same homes, rose 104% from 2015 to 2025 and rose 66% from 2020 to 2025, and moved +11.5% in 2025.
- Median home value (owners' estimate)
- $240,400
- Median gross rent
- $912
- Homes owned by their occupants
- 54.7%
- Housing units
- 6,812
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 81101?
465 business establishments had a location in this ZIP code in 2023, 24 fewer than in 2018; the most are in health care and social assistance (ZIP Code Business Patterns).
- Health care and social assistance73
- Retail trade70
- Accommodation and food services53
- Other services (except public administration)45
- Construction41
- Professional, scientific, and technical services38
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 81101?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 81146 | Mosca | 637 | $70k | 15.9 mi |
| 81123 | Blanca | 606 | $37k | 16.2 mi |
| 81144 | Monte Vista | 6,543 | $65k | 16.8 mi |
| 81151 | Sanford | 1,716 | $43k | 17.7 mi |
| 81140 | La Jara | 1,893 | $47k | 20.6 mi |
| 81136 | Hooper | 305 | $47k | 17.4 mi (near) |
| 81124 | Capulin | 259 | $89k | 18.9 mi (near) |
| 81141 | Manassa | 1,406 | $60k | 21.4 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.
Which other ZIP codes use the name Alamosa?
1 more ZIP code carries the postal name Alamosa, CO without a residential delivery area: PO boxes at the post office, or a single organization with its own ZIP code. The Census Bureau publishes no figures for it.
| ZIP | County |
|---|---|
| 81102 | Alamosa County |
Source: GeoNames postal codes (CC BY 4.0), downloaded 2026-10-09; a ZIP code with no Census ZCTA has no residential delivery area.