Union City, California Zip Codes
📍 Union City is in Alameda County, California with 1 zip code; the most populous is 94587.
Union City is a USPS city name in Alameda County, California with a Census population of approximately 69,502 across its ZIP codes. Alameda County as a whole has 73 ZIP codes in this directory. Below you'll find every zip code serving Union City with population, income and home value, a map, and the city's affordability profile.
Population and demographic data sourced from the U.S. Census Bureau American Community Survey (ACS) 5-Year Estimates. ZIP code routing data sourced from the United States Postal Service (USPS).
All Union City Zip Codes
Union City at a Glance
Union City has 1 ZIP code in this directory: 1 standard delivery ZIP. The 1 ZIP with published Census housing data cover 69,502 residents, the largest being 94587 with 69,502 people.
The median ZIP in Union City has a household income of $138,013 and a home value of $1,006,600, a price-to-income ratio of 7.3, above the 6.7 California ZIP median. Median rent across these ZIPs is $2,593 a month.
66% of households in the typical Union City ZIP own their home (statewide ZIP median 64%). 45% of adults hold a bachelor's degree, above the 31% statewide median. The median poverty rate is 6.6%, below the 10.8% statewide ZIP median. Overall density is about 3,546 residents per square mile across 20 square miles of ZIP land area.
Medians are taken across the ZIP codes listed below (each ZIP weighted equally); PO Box and no-data ZIPs are excluded. Definitions on the methodology page; statewide comparisons in the 2026 California ZIP Code Affordability Report.
Union City Zip Code Map
Interactive map of Union City, California zip codes. Click any marker for details.