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ZIP Code Database - Facts & Stats

Data Last Updated: March 1, 2023

ZIP Codes for City of San Marcos, TX

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Counties:HAYS, TX
Area Code(s):512, 737
Timezone(s):Central (GMT -06:00)
City Population:44,894 (More Details)
CBSA:Austin-Round Rock-Georgetown, TX
Congressional District(s):15, 21, 35
Land Area:678 square miles (county)
Water Area:2 square miles (county)

2 ZIP Codes

San Marcos, TX ZIP Code Boundaries

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San Marcos, TX Covers 2 ZIP Codes

ZIP CodeTypePopulation% of PopulationAliases
78667P.O. Box00.00%

San Marcos, TX Demographic Information *

Total population**44,894
Male population22,305
Female population22,589
Median age (years)23.1
White Population35,221
Black Population2,465
Indian Population383
Asian Population697
Hawaiian Population55
Hispanic Population16,967
Median age (Male)23.5
Median age (Female)22.7
Total households17,031
Family households (families)6,485
Average household size2.27
Average family size3.03
Total housing units18,179
* Demographic data is based on 2010 Census for the City of SAN MARCOS.
** City and ZIP Code Population will not be equal due to differences in their geographies.


  1. U.S. Postal Service [Last Updated: 2/1/2023],
  2. Internal Data Creation [Last Updated: 2/1/2023],
  3. U.S. Geological Survey [Updated as needed],
  4. U.S. Census [Updated Yearly],
  5. U.S. Census 2010 [Decennial] [Last Updated: 1/1/2010],