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US ZIP Code Profile

ZIP Code 78634
Hutto, Texas

ZIP code 78634 is in Hutto, located in Williamson County, Texas, within the Austin-Round Rock metro area. Its 2020 Census population was 37,951. The estimated median adjusted gross income per tax return is $62,794, and about 6% of filers report $200,000 or more.

2020 Population
37,951
Census ZCTA
County
Williamson
FIPS 48491
Median income (est.)
$62,794
IRS SOI 2022
Land Area
63.638 mi²
+ 0.396 mi² water

01Location & Geography

Authoritative geographic identifiers from the U.S. Census Bureau, ANSI, and FIPS standards.

Primary CityHutto, TX
CountyWilliamson County (FIPS 48491)
StateTexas (FIPS 48)
Metro Area (MSA)Austin-Round Rock, TX Metro Area (12420)
Census Region / DivisionSouth Region · West South Central Division
Coordinates30.560604, -97.54626
Land / Water Area63.638 mi² land · 0.396 mi² water

02Income & Economics

Distribution of the 22,320 individual tax returns filed in 78634 by adjusted gross income bracket (IRS SOI, 2022).

< $25K
19.7%
$25K–$50K
21.5%
$50K–$75K
17.2%
$75K–$100K
12.9%
$100K–$200K
23.1%
$200K+
5.7%
The $200,000+ bracket accounts for 24% of 78634's total adjusted gross income, from 6% of returns — a concentration that drives the gap between the median ($62,794) and the average.
Estimated median = median adjusted gross income per tax return, interpolated from IRS SOI brackets. Differs from U.S. Census household income.

03Income Over Time

Year-over-year change in 78634's IRS income metrics, 2020–2022.

Median income (2021→2022)
$62,794
▲ 9.0%
Filers earning $200K+
5.7%
▲ 1.3 pt
Total filers
22,320
▲ 9.5%
GET /zipc/v2/zipcodes/78634/soi?year=… $53K 2020 $58K 2021 $63K 2022
Median = adjusted gross income per return, interpolated from IRS SOI brackets. Figures are nominal (not inflation-adjusted).

04Population Trend

Decennial U.S. Census population for the 78634 ZCTA.

2000
3,912
 
2010
22,791
▲ +482.6%
2020
37,951
▲ +66.5%

05USPS Postal Details

Delivery and facility attributes from the monthly USPS dataset.

ZIP ClassificationNon-Unique Zip
Facility TypePost Office
Carrier Route SortD
USPS Finance Number484235
City AliasesHutto, Monadale

06Frequently Asked Questions

What county is ZIP code 78634 in?

ZIP code 78634 is in Williamson County, Texas (county FIPS code 48491).

What city is ZIP code 78634?

The primary USPS city for 78634 is Hutto, TX.

What metro area (MSA) is 78634 in?

78634 is part of the Austin-Round Rock, TX Metro Area (MSA code 12420).

What is the population of ZIP code 78634?

The 2020 Census population of 78634 was 37,951 residents.

What is the median income in ZIP code 78634?

Based on IRS Statistics of Income data, the estimated median adjusted gross income per tax return in 78634 is about $62,794, with around 6% of filers reporting $200,000 or more. Note that adjusted gross income is a tax measure and differs from U.S. Census household income.