County ZIP codes · Texas · FIPS 48015

Austin County, TX ZIP Codes

Austin County, Texas has 14 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 13 residential and 1 for PO boxes or a single organization. 7 of the residential ones lie mainly in Austin County and 6 mainly in a neighboring county; 9 cross the county line. Median household income ranges from $68,444 in 78933 (Cat Spring) to $109,917 in 77835 (Burton) (Census Bureau, ACS 2020-2024).

ACS2020-24
Census2020

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are its ZIP codes?

78933 · $68k 77835 · $110k

The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $73,388 and $89,157.

They carry 13 postal town names.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).

All 13 residential ZIP codes in Austin County

7 ZIP codes lie mainly in Austin County; 6 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Austin County, largest first; "In this county" is the share of the ZIP's land in the county
						In this county
77474	Sealy	15,146	73	$75k	$288k	98%
77418	Bellville	10,171	55	$91k	$344k	100%
77485	Wallis	4,378	57	$52k	$225k	60%
78950	New Ulm	2,300	20	$91k	$248k	69%
78944	Industry	720	47	$127k	$384k	100%
78931	Bleiblerville	185	14	–	–	100%
77473	San Felipe	49	490	–	–	100%

Partly in Austin County

Residential ZIP codes mainly in another county that reach at least 1% into Austin County, by their share here
						In this county
78933	Cat Spring	1,395	11	$68k	$273k	30%
77426	Chappell Hill	2,007	22	$80k	$592k	21%
77833	Brenham	29,498	94	$73k	$281k	8%
78954	Round Top	1,173	16	$104k	$427k	8%
78940	Fayetteville	2,188	17	$89k	$292k	8%
77835	Burton	2,569	23	$110k	$395k	1%

Download the 14 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).

Which ZIP codes cross the county line?

9 ZIP codes of Austin County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Austin County and in the neighboring counties
ZIP	In Austin	Elsewhere
77833	8%	Washington County 92%
77474	98%	Colorado County 2%
77485	60%	Fort Bend County 40%
77835	1%	Washington County 99%
78950	69%	Colorado County 28%; Fayette County 3%
78940	8%	Fayette County 76%; Colorado County 17%
77426	21%	Washington County 79%
78933	30%	Colorado County 70%
78954	8%	Fayette County 92%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

PO Box and single-organization ZIP codes

ZIP codes in Austin County without a residential area (GeoNames postal codes)
ZIP	Postal name
77452	Kenney

Source: GeoNames postal codes (CC BY 4.0).

Which first three digits do Austin County's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Austin County's ZIP codes use 3 prefixes: 774, 778 and 789.

Three-digit prefixes of Austin County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Austin County's
Prefix	Sectional center	Here	All codes
774	South Houston, TX (SCF 774)	6	83
778	North Houston, TX (SCF 773)	2	47
789	Austin, TX (SCF 786)	6	28

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.

Where are the ZIP codes of Austin County?