Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — CITY/TX/SAN-MARCOS

San Marcos ZIP codes, Texas

San Marcos, TX has 2 ZIP codes (78666 and 78667) and area codes 512 and 737. The largest is 78666.

USPS city name
2 ZIP codes
Overlapping the city
3 more
Population
70,897
Area codes
512, 737
State
Texas

Mail addressed to San Marcos uses the ZIP codes above. 3 more ZIP codes cover part of the city but are addressed as somewhere else; they are listed separately below.

San Marcos in numbers

About 70,897 people live in San Marcos, in 28,013 households. The median household income is $51,281 a year, 35% below the Texas median of $78,476 (US: $80,734). The median owner-occupied home is valued at $310,400 (9% above the Texas median), and median gross rent is $1,322 a month. The median age is 25.5; 38.3% of adults 25 and over hold a bachelor's degree or higher (33.8% across Texas); the average commute takes 24 minutes.

Population70,897San Marcos70,897
Households28,013San Marcos28,013
Median age25.5San Marcos25.5Texas35.6US 38.9
Median household income$51,281San Marcos$51,281Texas$78,476US $80,734
Median home value$310,400San Marcos$310,400Texas$283,800US $332,700
Median gross rent$1,322San Marcos$1,322Texas$1,403US $1,413
Bachelor's degree or higher38.3%San Marcos38.3%Texas33.8%US 35.7%
Mean commute24.0 minSan Marcos24.0 minTexas26.7 minUS 26.4 min
Population density1,776 / sq miSan Marcos1,776 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, for the census place San Marcos city. Survey estimates carry margins of error, wider for small places. Sources and methods.

ZIP codes addressed as San Marcos

ZIP codes with the USPS city name San Marcos
ZIP City Type Population Median income Median home
78666 San Marcos , TX Standard 88,583 $54,737 $306,700
78667 San Marcos , TX No street area — — —

Other ZIP codes overlapping San Marcos

These ZIP codes cover part of San Marcos but are addressed as somewhere else.

ZIP codes overlapping San Marcos
ZIP City Type Population Median income Median home
78640 Kyle , TX Standard 77,531 $90,075 $330,400
78655 Martindale , TX Standard 3,730 $55,952 $269,900
78656 Maxwell , TX Standard 2,847 $81,346 $238,100

Map of San Marcos ZIP codes

7866678667

The ZIP codes of San Marcos, TX, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Towns near San Marcos

The nearest larger towns are New Braunfels (104,643 people, 16 mi), Austin (979,539 people, 31 mi) and Cedar Park (78,301 people, 45 mi).

Towns near San Marcos
TownPopulationDistance
Redwood 3,441 4.7 mi
Kyle 56,823 8.9 mi
Uhland 2,520 11.0 mi
Wimberley 2,891 12.0 mi
Buda 15,859 15.1 mi
Lockhart 15,326 15.2 mi
New Braunfels 104,643 16.1 mi
Canyon Lake 33,883 19.4 mi
Seguin 33,754 19.7 mi
Shady Hollow 5,709 20.6 mi
Luling 5,531 21.9 mi
Belterra 6,978 21.9 mi
Dripping Springs 7,405 24.2 mi
Garden Ridge 4,332 26.9 mi

More nearby: every ZIP code in Hays County · Texas ZIP codes

Cite this page

zipcodes.pro. “San Marcos, TX ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/city/tx/san-marcos

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