San Geronimo, California Zip Codes
📍 San Geronimo is in Marin County, California with 1 zip code; the most populous is 94963.
San Geronimo is a USPS city name in Marin County, California with a Census population of approximately 462 across its ZIP codes. Marin County as a whole has 42 ZIP codes in this directory. Below you'll find every zip code serving San Geronimo 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 San Geronimo Zip Codes
San Geronimo at a Glance
San Geronimo has 1 ZIP code in this directory: 1 standard delivery ZIP. The 1 ZIP with published Census housing data cover 462 residents, the largest being 94963 with 462 people.
The median ZIP in San Geronimo has a household income of $215,375 and a home value of $1,103,600, a price-to-income ratio of 5.1, below the 6.7 California ZIP median.
90% of households in the typical San Geronimo ZIP own their home (statewide ZIP median 64%). 86% of adults hold a bachelor's degree, far above the 31% statewide median. Overall density is about 289 residents per square mile across 2 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.
San Geronimo Zip Code Map
Interactive map of San Geronimo, California zip codes. Click any marker for details.