Residential delivery area · Texas
ZIP Code 78155: Seguin, TX
ZIP code 78155 uses the postal name Seguin, Texas and lies entirely in Guadalupe County (Census 2020 ZIP-county file). About 56,000 people live there (Census Bureau, ACS 2020-2024). Median household income is $71,039 (Census Bureau, ACS 2020-2024). By Census place, its land lies in Seguin (11%), Geronimo (2%) and New Berlin (2%); 85% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Seguin · its only residential ZIP
- County
- Guadalupe County
- Census places
- Seguin (11%); Geronimo (2%) census-designated place; New Berlin (2%)
- Metro area
- San Antonio-New Braunfels, TX
- House districts
- TX-15 (90%), TX-28 (10%) 119th Congress, by share of land
- State
- Texas
- Time zone
- Central
- Land area
- 355.5 sq mi · 156 people per sq mi
- PO Box ZIPs
- 78156 also use the name Seguin
Where is ZIP code 78155?
78155 centers on 29.537°, -97.937° and covers 355.5 square miles of land plus 1.5 of water. It borders 10 ZIP codes: 78123, 78638, 78124, 78130, 78122, 78121, 78140, 78160, 78666, 78629.
The map draws ZIP code areas only. For the streets inside 78155, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 78155 compare with the rest of Guadalupe County?
| Measure | 78155 | In Guadalupe County | In TX |
|---|---|---|---|
| People (ACS 2020-2024) | 55,600 | 3rd of 13 | 103rd of 1,990 |
| Median household income | $71k | 6th of 9 | 614th of 1,172 |
| Median home value | $267k | 6th of 8 | 465th of 1,172 |
Its median household income is higher than in 48% of U.S. residential ZIP codes, and it is denser than 60% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 78155?
The 2020 Census counted 51,772 people in 78155; the ACS, which samples households over 2020-2024, estimates 55,600. Between the 2010 and 2020 censuses its population grew 14.2% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 55,600
- 2020 Census count
- 51,772+14.2% since 2010 (45,341)
- Households
- 21,007
- Median age
- 39.4
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 78155?
Of the 55,600 people the ACS estimates in 78155, 21.8% are under 18 and 17.9% are 65 or older. The largest group by race and Hispanic origin is Hispanic or Latino (50.1%), then White (not Hispanic) (41.8%).
- Under 1821.8%
- 18 to 6460.4%
- 65 and older17.9%
- Hispanic or Latino50.1%
- White, not Hispanic41.8%
- Black, not Hispanic4.5%
- Other or two or more3.1%
- Asian, not Hispanic0.5%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 78155 earn?
Median household income is $71,039 (ACS 2020-2024), the 6th highest of the 9 ranked ZIP codes in Guadalupe County. It is not measurably different from 2015-2019 ($71,170 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $71,039
- Income per person
- $36,571
- Below the poverty line
- 16.9%
- Unemployed (of the labor force)
- 3.9%
- Adults 25+ with a bachelor's degree
- 21.7%
- Adjusted gross income per tax return, 2022
- $70,53426,050 returns; wages 69% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 78155?
FHFA's house price index for 78155, built from repeat sales and appraisals of the same homes, rose 88% from 2015 to 2025 and rose 44% from 2020 to 2025, and moved −1.1% in 2025.
- Median home value (owners' estimate)
- $266,700
- Median gross rent
- $1,198
- Homes owned by their occupants
- 72.5%
- Housing units
- 22,688
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 78155?
1,065 business establishments had a location in this ZIP code in 2023, 133 more than in 2018; the most are in retail trade (ZIP Code Business Patterns).
- Retail trade160
- Construction116
- Health care and social assistance104
- Accommodation and food services104
- Other services (except public administration)104
- Manufacturing73
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 78155?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 78123 | McQueeney | 2,127 | $98k | 7.7 mi |
| 78638 | Kingsbury | 2,135 | $69k | 12.4 mi |
| 78124 | Marion | 6,157 | $74k | 12.7 mi |
| 78130 | New Braunfels | 104,009 | $83k | 13.4 mi |
| 78122 | Leesville | 338 | – | 14.8 mi |
| 78121 | La Vernia | 16,120 | $120k | 15.8 mi |
| 78140 | Nixon | 3,474 | $50k | 19.0 mi |
| 78160 | Stockdale | 4,885 | $65k | 20.3 mi |
| 78666 | San Marcos | 88,583 | $55k | 24.0 mi |
| 78629 | Gonzales | 12,740 | $60k | 29.6 mi |
| 78661 | Prairie Lea | 835 | $83k | 16.6 mi (near) |
| 78670 | Staples | 130 | $79k | 16.6 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.
Which other ZIP codes use the name Seguin?
1 more ZIP code carries the postal name Seguin, TX without a residential delivery area: PO boxes at the post office, or a single organization with its own ZIP code. The Census Bureau publishes no figures for it.
| ZIP | County |
|---|---|
| 78156 | Guadalupe County |
Source: GeoNames postal codes (CC BY 4.0), downloaded 2026-10-09; a ZIP code with no Census ZCTA has no residential delivery area.