Residential delivery area · California
ZIP Code 91001: Altadena, CA
ZIP code 91001 is in Altadena, California, entirely in Los Angeles County (Census 2020 ZIP-county file). About 35,000 people live there (Census Bureau, ACS 2020-2024). Median household income is $134,903 (Census Bureau, ACS 2020-2024). By Census place, 94% of its land lies in Altadena (a census-designated place), and 4% in smaller places; 2% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Altadena · its only residential ZIP
- County
- Los Angeles County
- Census places
- Altadena census-designated place
- Metro area
- Los Angeles-Long Beach-Anaheim, CA
- House district
- CA-28 119th Congress
- State
- California
- Time zone
- Pacific
- Land area
- 8.3 sq mi · 4,295 people per sq mi
- PO Box ZIPs
- 91003 also use the name Altadena
Where is ZIP code 91001?
91001 centers on 34.194°, -118.138° and covers 8.3 square miles of land plus 0.0 of water. It borders 4 ZIP codes: 91104, 91103, 91107, 91011.
The map draws ZIP code areas only. For the streets inside 91001, 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 91001 compare with the rest of Los Angeles County?
| Measure | 91001 | In Los Angeles County | In CA |
|---|---|---|---|
| People (ACS 2020-2024) | 35,475 | 120th of 301 | 477th of 1,802 |
| Median household income | $135k | 37th of 265 | 242nd of 1,189 |
| Median home value | $1.14M | 65th of 273 | 264th of 1,317 |
Its median household income is higher than in 94% of U.S. residential ZIP codes, and it is denser than 92% 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 91001?
The 2020 Census counted 36,578 people in 91001; the ACS, which samples households over 2020-2024, estimates 35,475. Between the 2010 and 2020 censuses its population grew 1.3% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 35,475
- 2020 Census count
- 36,578+1.3% since 2010 (36,126)
- Households
- 12,587
- Median age
- 46.3
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 91001?
Of the 35,475 people the ACS estimates in 91001, 19.6% are under 18 and 22.0% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (36.9%), then Hispanic or Latino (28.6%).
- Under 1819.6%
- 18 to 6458.4%
- 65 and older22.0%
- White, not Hispanic36.9%
- Hispanic or Latino28.6%
- Black, not Hispanic20.0%
- Other or two or more8.3%
- Asian, not Hispanic6.2%
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 91001 earn?
Median household income is $134,903 (ACS 2020-2024), the 37th highest of the 265 ranked ZIP codes in Los Angeles County. It is not measurably different from 2015-2019 ($124,001 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $134,903
- Income per person
- $68,163
- Below the poverty line
- 7.4%
- Unemployed (of the labor force)
- 7.4%
- Adults 25+ with a bachelor's degree
- 53.9%
- Adjusted gross income per tax return, 2022
- $133,51217,260 returns; wages 63% 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 91001?
FHFA's house price index for 91001, built from repeat sales and appraisals of the same homes, rose 85% from 2015 to 2025 and rose 40% from 2020 to 2025, and moved −4.4% in 2025.
- Median home value (owners' estimate)
- $1,135,200
- Median gross rent
- $2,437
- Homes owned by their occupants
- 79.9%
- Housing units
- 13,216
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 91001?
752 business establishments had a location in this ZIP code in 2023, 152 more than in 2018; the most are in professional, scientific, and technical services (ZIP Code Business Patterns).
- Professional, scientific, and technical services146
- Health care and social assistance112
- Arts, entertainment, and recreation86
- Construction52
- Information51
- Retail trade49
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 91001?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 91104 | Pasadena | 35,937 | $106k | 2.2 mi |
| 91103 | Pasadena | 25,142 | $94k | 2.4 mi |
| 91107 | Pasadena | 32,316 | $126k | 3.8 mi |
| 91011 | La Canada Flintridge | 19,935 | $242k | 4.0 mi |
| 91101 | Pasadena | 21,165 | $88k | 3.3 mi (near) |
| 91106 | Pasadena | 23,910 | $90k | 3.8 mi (near) |
| 91125 | Pasadena | 1,000 | – | 4.0 mi (near) |
| 91105 | Pasadena | 12,531 | $157k | 4.1 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 Altadena?
1 more ZIP code carries the postal name Altadena, CA 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 |
|---|---|
| 91003 | Los Angeles 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.