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ZIP Code Database - Facts & Stats

Data Last Updated: May 1, 2022

Zip Code 78666, San Marcos, TX

ZIP Code 78666 Details

Zip Code:78666
City:San Marcos
State:TX [Texas]
Counties:HAYS, TX
Multi County:Yes
City Alias(es):San Marcos
Area Code:512 / 737
City Type:P [Post Office]
Classification: [Non-Unique]
Time Zone:Central (GMT -06:00)
Observes Daylight Saving:Yes
Elevation:767 ft
State FIPS:48
County FIPS:209
Division:West South Central
Intro Date:<2004-10

ZIP Code 78666 2010 Census Demographics

Current Population:78,219
2010 Population:63,836
Households per ZIP Code:22,874
Average House Value:$186,400
Avg. Income Per Household:$45,660
Persons Per Household:2.44
White Population:51,545
Black Population:3,565
Hispanic Population:25,958
Asian Population:1,467
American Indian Population:971
Hawaiian Population:148
Other Population:8,082
Male Population:32,138
Female Population:31,698
Median Age:23.90 years
Male Median Age:24.00 years
Female Median Age:23.70 years

ZIP Code 78666 Other Demographics

# Residential Mailboxes:32,057
# Business Mailboxes:2,246
Total Delivery Receptacles:52,781
Number of Businesses:1719
1st Quarter Payroll:$252,842,000
Annual Payroll:$1,058,334,000
# of Employees:32,759
Water Area:0.93 sq mi
Land Area:176.603 sq mi
113th Congressional District:15|21|25|35
113th Congressional Land Area:7804.07|5920.89|7620.7|593.77 sq mi
Single Family Delivery Units:11,614
Multi Family Delivery Units:11,744
# Residential Mailboxes:32,057
# Business Mailboxes:2,246
Total Delivery Receptacles:52,781

ZIP Code 78666 Social Security Benefits

  2018 2019 Delta
Total Beneficiaries: 8,360 8,790 +430
Retired Workers: 5,720 6,100 +380
Disabled Workers: 1,105 1,120 +15
Widow(er)s and Parents: 590 615 +25
Spouses: 340 355 +15
Children: 605 600 -5
65+: 6,215 6,645 +430
Monthly Benefits - All: $10,767,000 $11,717,000 +$950,000
Monthly Benefits - Retired Workers: $8,071,000 $8,888,000 +$817,000
Monthly Benefits - Widow(ers): $770,000 $825,000 +$55,000

ZIP Code 78666 Statistical Areas

CBSA: 12420
CBSA Name: Austin-Round Rock-Georgetown, TX
CBSA Type: Metro
CBSA Division: 
CBSA Division Name: 
CBSA Population:1,716,289
CBSA Division Population:0
MSA: 0640
MSA Name: Austin-San Marcos, TX MSA
PMSA Name: 
City State Key:W25520
Preferred Last Line Key:W25520
78665: Previous ZIP Code
Next ZIP Code: 78667


  1. U.S. Postal Service [Last Updated: 5/1/2022],
  2. Internal Data Creation [Last Updated: 5/1/2022],
  3. U.S. Geological Survey [Updated as needed],
  4. U.S. Census [Updated Yearly],
  5. U.S. Census American National Standards Institute (ANSI) [Last Updated: 5/1/2022],
  6. U.S. Census 2010 [Decennial] [Last Updated: 1/1/2010],
  7. Centers for Medicare & Medicaid Services [Updated Yearly],