| City: | Montrose, California |
| County: | Los Angeles County |
| Timezone: | Pacific (GMT -08:00) |
| Local Time: | 10:01:38 PM |
| Population: | No Population Data |
| Area Code: | 818 |
| Classification: | PO Box |
| Coordinates: | 34.2067, -118.2236 |
| Quick Link: |
ZIP code 91021 serves as the PO Box ZIP for Montrose, California, a small community nestled in the foothills of the San Gabriel Mountains in Los Angeles County. This isn't a standalone delivery area. Instead, it's a point location entirely contained within ZIP 91020, sharing the La Crescenta-Montrose neighborhood.
The post office maintains 318 PO Boxes and serves 155 registered businesses. All mail for this ZIP routes through a single address on Montrose Avenue, where 48 delivery points share the street. The 91021 ZIP exists solely for PO Box customers at the Montrose post office.
Montrose sits within the greater Glendale area, bordered by La Canada Flintridge to the east and neighborhoods like Sparr Heights and Montecito Park to the south. The community has a distinct small-town feel despite being part of the Los Angeles metropolitan area. Local shops and restaurants line Honolulu Avenue in the Montrose Shopping Park.
For mail, 91021 is exclusively a PO Box ZIP. There's no residential street delivery under this code. Residents and businesses who want a Montrose PO Box use 91021, while street delivery in the same neighborhood uses the sibling ZIP 91020.
The single street record is the post office address on Montrose Avenue.
ZIP Code 91021 supports both business and residential activity. According to the Business Census (2024), there are 9 business establishments, employing about 9 people with an annual payroll of $505,000.
| # Residential Mailboxes: | 0Source: USPS |
| # Business Mailboxes: | 0Source: USPS |
| Total Delivery Receptacles: | 594Source: USPS |
| Single Family Delivery Units: | 0Source: USPS |
| Multi Family Delivery Units: | 0Source: USPS |
| # of Businesses: | 9Source: CBP |
| 1st Quarter Payroll: | $92,000Source: CBP |
| Annual Payroll: | $505,000Source: CBP |
| # of Employees: | 9Source: CBP |
ZIP Code 91021 is located in Los Angeles County, California, within the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area (CBSA 31080) and California's 28th Congressional District. This Metro area has a population of 13,012,469 people, about 0.00% of whom live in ZIP Code 91021, and is subdivided into the Los Angeles-Long Beach-Glendale, CA division. It covers 0 sq mi of land and a water area of 0 sq mi.
| CBSA Name: | Los Angeles-Long Beach-Anaheim, CASource: Census |
| CBSA Number: | 31080Source: Census |
| CBSA Type: | MetroSource: Census |
| CBSA Division: | Los Angeles-Long Beach-Glendale, CA (CBSA Div 31084)Source: Census |
| CBSA Population: | 13,012,469Source: Census |
| MSA: | Los Angeles-Riverside-Orange County, CASource: Census |
| Land Area: | --Source: Census |
| Water Area: | --Source: Census |
| Congressional District: | 28Source: USPS |
| Congressional Land Area: | 218.45 sq miSource: Census |
| PMSA: | Los Angeles-Long Beach, CA PMSASource: Census |
| Intro Date: | < 2004-10Source: ZIP-Codes.com |
| Place FIPS Code: | 0639045Source: Census |
| Place Name: | La Crescenta-Montrose CDP; CaliforniaSource: Census |
We could not locate which school district 91021 belongs to, but we will update this once new district data is released. There are no public schools nor private schools with a mailing address in this ZIP Code. Listing Nearby schools instead. It also has 6 colleges, universities or post secondary education institutions nearby which would be a short commute to.
Our sources include trusted federal and licensed data from the United States Postal Service, U.S. Census Bureau, U.S. Geological Survey, Centers for Medicare & Medicaid Services, and the National Center for Education Statistics, along with proprietary datasets created by ZIP-Codes.com. Data last updated on January 1, 2026.