Get API Key →
US ZIP Code Profile

ZIP Code 78731
Austin, Texas

ZIP code 78731 is in Austin, located in Travis County, Texas, within the Austin-Round Rock metro area. Its 2020 Census population was 27,240. The estimated median adjusted gross income per tax return is $97,313, and about 31% of filers report $200,000 or more.

2020 Population
27,240
Census ZCTA
County
Travis
FIPS 48453
Median income (est.)
$97,313
IRS SOI 2022
Land Area
8.663 mi²
+ 0.16 mi² water

01Location & Geography

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

Primary CityAustin, TX
CountyTravis County (FIPS 48453)
StateTexas (FIPS 48)
Metro Area (MSA)Austin-Round Rock, TX Metro Area (12420)
Census Region / DivisionSouth Region · West South Central Division
Coordinates30.348244, -97.76814
Land / Water Area8.663 mi² land · 0.16 mi² water

02Income & Economics

Distribution of the 14,190 individual tax returns filed in 78731 by adjusted gross income bracket (IRS SOI, 2022).

< $25K
16.6%
$25K–$50K
14.7%
$50K–$75K
12.0%
$75K–$100K
7.5%
$100K–$200K
17.9%
$200K+
31.3%
The $200,000+ bracket accounts for 84% of 78731's total adjusted gross income, from 31% of returns — a concentration that drives the gap between the median ($97,313) 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 78731's IRS income metrics, 2020–2022.

Median income (2021→2022)
$97,313
▼ 0.0%
Filers earning $200K+
31.3%
▼ 1.4 pt
Total filers
14,190
▲ 2.8%
GET /zipc/v2/zipcodes/78731/soi?year=… $83K 2020 $97K 2021 $97K 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 78731 ZCTA.

2000
24,059
 
2010
24,614
▲ +2.3%
2020
27,240
▲ +10.7%

05Nearby ZIP Codes — Live Radius Search

Drag the slider to filter ZIP codes by distance from 78731. Powered by the same radius endpoint developers call from the API.

GET /zipc/v2/radius

ZIP codes within range of 78731

Austin and its immediate neighbors, sorted by distance.

3 mi
GET /zipc/v2/distance

Distance from 78731 to any ZIP

Enter a 5-digit ZIP to calculate the distance.

06USPS 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, Camp Mabry

07Frequently Asked Questions

What county is ZIP code 78731 in?

ZIP code 78731 is in Travis County, Texas (county FIPS code 48453).

What city is ZIP code 78731?

The primary USPS city for 78731 is Austin, TX.

What metro area (MSA) is 78731 in?

78731 is part of the Austin-Round Rock, TX Metro Area (MSA code 12420).

What is the population of ZIP code 78731?

The 2020 Census population of 78731 was 27,240 residents.

What is the median income in ZIP code 78731?

Based on IRS Statistics of Income data, the estimated median adjusted gross income per tax return in 78731 is about $97,313, with around 31% of filers reporting $200,000 or more. Note that adjusted gross income is a tax measure and differs from U.S. Census household income.