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US ZIP Code Profile

ZIP Code 78957
Smithville, Texas

ZIP code 78957 is in Smithville, located in Bastrop County, Texas, within the Austin-Round Rock metro area. Its 2020 Census population was 10,214. The estimated median adjusted gross income per tax return is $48,649, and about 6% of filers report $200,000 or more.

2020 Population
10,214
Census ZCTA
County
Bastrop
FIPS 48021
Median income (est.)
$48,649
IRS SOI 2022
Land Area
187.195 mi²
+ 2.077 mi² water

01Location & Geography

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

Primary CitySmithville, TX
CountyBastrop County (FIPS 48021)
StateTexas (FIPS 48)
Metro Area (MSA)Austin-Round Rock, TX Metro Area (12420)
Census Region / DivisionSouth Region · West South Central Division
Coordinates30.013882, -97.1821
Land / Water Area187.195 mi² land · 2.077 mi² water

02Income & Economics

Distribution of the 4,520 individual tax returns filed in 78957 by adjusted gross income bracket (IRS SOI, 2022).

< $25K
26.8%
$25K–$50K
24.6%
$50K–$75K
16.2%
$75K–$100K
10.2%
$100K–$200K
16.6%
$200K+
5.8%
The $200,000+ bracket accounts for 31% of 78957's total adjusted gross income, from 6% of returns — a concentration that drives the gap between the median ($48,649) 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 78957's IRS income metrics, 2020–2022.

Median income (2021→2022)
$48,649
▲ 8.7%
Filers earning $200K+
5.8%
▲ 1.1 pt
Total filers
4,520
▲ 0.9%
GET /zipc/v2/zipcodes/78957/soi?year=… $43K 2020 $45K 2021 $49K 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 78957 ZCTA.

2000
8,451
 
2010
9,067
▲ +7.3%
2020
10,214
▲ +12.7%

05USPS Postal Details

Delivery and facility attributes from the monthly USPS dataset.

ZIP ClassificationNon-Unique Zip
Facility TypePost Office
Carrier Route SortD
USPS Finance Number488450
City AliasesKirtley, Smithville, Upton

06Frequently Asked Questions

What county is ZIP code 78957 in?

ZIP code 78957 is in Bastrop County, Texas (county FIPS code 48021).

What city is ZIP code 78957?

The primary USPS city for 78957 is Smithville, TX.

What metro area (MSA) is 78957 in?

78957 is part of the Austin-Round Rock, TX Metro Area (MSA code 12420).

What is the population of ZIP code 78957?

The 2020 Census population of 78957 was 10,214 residents.

What is the median income in ZIP code 78957?

Based on IRS Statistics of Income data, the estimated median adjusted gross income per tax return in 78957 is about $48,649, 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.