ZIP Code 91903

91903 is one of California's ZIP codes, delivering to addresses in Alpine, San Diego County.

City: Alpine
County: San Diego County
State: California
Prefix: 919xx

Where this code sits

91903 is part of the 919xx range, the group of codes handled by one mail processing centre. Alpine is served by 2 ZIP codes in total.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 91903 delivers to without sharing its boundary.

ZIP codes nearest 91903

The ZIP codes whose reference points sit closest to 91903.
ZIP code	Distance	Delivers to
ZIP code 91901	0.8 mi	Alpine, CA
ZIP code 92040	9.0 mi	Lakeside, CA
ZIP code 91935	9.1 mi	Jamul, CA
ZIP code 92021	9.1 mi	El Cajon, CA
ZIP code 92019	9.7 mi	El Cajon, CA
ZIP code 91916	9.9 mi	Descanso, CA
ZIP code 92022	12 mi	El Cajon, CA
ZIP code 92020	12 mi	El Cajon, CA

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 91903, plotted from its record coordinates.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope ZIP code 91903. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.