Youngest ZIP codes in Guadalupe County, TX
These are the 11 ZIP codes in Guadalupe County with the lowest median age, out of 11 with at least 1,000 residents. 78666 (San Marcos, 26.9), 78108 (Cibolo, 35.5) and 78130 (New Braunfels, 36.1) lead the list. There is no single "best" ZIP code in Guadalupe County; the right one depends on who you want to reach, so the same ZIP codes are ranked several ways below.
Youngest ZIP codes in Guadalupe County
| Rank | ZIP | Mailing city | Median age | Residents | Households | Residential mailboxes |
|---|---|---|---|---|---|---|
| 1 | 78666 | San Marcos | 26.9 ±0.6 | 88,583 | 33,949 | 40,618 |
| 2 | 78108 | Cibolo | 35.5 ±1.0 | 49,784 | 15,914 | 18,386 |
| 3 | 78130 | New Braunfels | 36.1 ±0.8 | 104,009 | 40,747 | 48,800 |
| 4 | 78121 | La Vernia | 38.2 ±1.1 | 16,120 | 5,274 | 6,223 |
| 5 | 78154 | Schertz | 38.9 ±1.8 | 41,907 | 15,558 | 17,676 |
| 6 | 78155 | Seguin | 39.4 ±2.0 | 55,600 | 21,007 | 26,649 |
| 7 | 78648 | Luling | 43.9 ±5.6 | 7,863 | 3,274 | 3,344 |
| 8 | 78655 | Martindale | 44.6 ±15.0 | 3,730 | 1,388 | 919 |
| 9 | 78638 | Kingsbury | 45.4 ±11.4 | 2,135 | 706 | 1,121 |
| 10 | 78124 | Marion | 46.6 ±6.2 | 6,157 | 2,378 | 3,954 |
| 11 | 78123 | Mc Queeney | 48.9 ±21.0 | 2,127 | 878 | 1,083 |
How we ranked them
Ranked by median age of all residents, lowest first (ACS 5-year estimates, 2020–2024). ZIP codes need at least 1,000 residents to be ranked; 11 of 12 qualify.
Which of these to mail, and why
Younger ZIP codes skew toward renters, students and young families: fitness, quick-service food, apartments, entertainment and first-time-buyer offers.
The top five ZIP codes on this list hold 111,442 households, on 154 carrier routes with 131,703 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.
Open 78666 on the EDDM route map
More rankings
- Richest ZIP codes in Guadalupe County
- ZIP codes with the highest home values in Guadalupe County
- ZIP codes with the highest homeownership in Guadalupe County
- ZIP codes with the most families with kids in Guadalupe County
- ZIP codes with the most new movers in Guadalupe County
- Oldest ZIP codes in Guadalupe County
- Fastest-growing ZIP codes in Guadalupe County
- Youngest ZIP codes in the San Antonio area
- All Guadalupe County ZIP codes
Businesses that mail these ZIP codes
Map it and price it
EDDM guides
Frequently asked questions
- Which ZIP code in Guadalupe County has the lowest median age?
- 78666 (San Marcos), at 26.9 (±0.6), among 11 ZIP codes with at least 1,000 residents.
- How is this ranking calculated?
- Ranked by median age of all residents, lowest first (ACS 5-year estimates, 2020–2024).
- Why are some ZIP codes missing?
- ZIP codes with fewer than 1,000 residents are left out because their survey estimates swing too much to rank, and so are ZIP codes where the Census Bureau did not publish this figure.
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.