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US ZIP Code Profile

ZIP Code 78737
Austin, Texas

ZIP code 78737 is in Austin, located in Hays County, Texas, within the Austin-Round Rock metro area. Its 2020 Census population was 20,996. The estimated median adjusted gross income per tax return is $137,397, and about 35% of filers report $200,000 or more.

2020 Population
20,996
Census ZCTA
County
Hays
FIPS 48209
Median income (est.)
$137,397
IRS SOI 2022
Land Area
37.945 mi²
+ 0.002 mi² water

01Location & Geography

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

Primary CityAustin, TX
CountyHays County (FIPS 48209)
StateTexas (FIPS 48)
Metro Area (MSA)Austin-Round Rock, TX Metro Area (12420)
Census Region / DivisionSouth Region · West South Central Division
Coordinates30.189936, -97.95664
Land / Water Area37.945 mi² land · 0.002 mi² water

02Income & Economics

Distribution of the 10,370 individual tax returns filed in 78737 by adjusted gross income bracket (IRS SOI, 2022).

< $25K
16.3%
$25K–$50K
10.2%
$50K–$75K
8.0%
$75K–$100K
6.8%
$100K–$200K
23.3%
$200K+
35.4%
The $200,000+ bracket accounts for 76% of 78737's total adjusted gross income, from 35% of returns — a concentration that drives the gap between the median ($137,397) 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 78737's IRS income metrics, 2020–2022.

Median income (2021→2022)
$137,397
▲ 3.6%
Filers earning $200K+
35.4%
▲ 1.8 pt
Total filers
10,370
▲ 3.1%
GET /zipc/v2/zipcodes/78737/soi?year=… $117K 2020 $133K 2021 $137K 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 78737 ZCTA.

2000
7,100
 
2010
12,081
▲ +70.2%
2020
20,996
▲ +73.8%

05USPS Postal Details

Delivery and facility attributes from the monthly USPS dataset.

ZIP ClassificationNon-Unique Zip
Facility TypePost Office
Carrier Route SortD
USPS Finance Number480420
City AliasesAustin

06Frequently Asked Questions

What county is ZIP code 78737 in?

ZIP code 78737 is in Hays County, Texas (county FIPS code 48209).

What city is ZIP code 78737?

The primary USPS city for 78737 is Austin, TX.

What metro area (MSA) is 78737 in?

78737 is part of the Austin-Round Rock, TX Metro Area (MSA code 12420).

What is the population of ZIP code 78737?

The 2020 Census population of 78737 was 20,996 residents.

What is the median income in ZIP code 78737?

Based on IRS Statistics of Income data, the estimated median adjusted gross income per tax return in 78737 is about $137,397, with around 35% of filers reporting $200,000 or more. Note that adjusted gross income is a tax measure and differs from U.S. Census household income.