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US ZIP Code Profile

ZIP Code 78588
San Isidro, Texas

ZIP code 78588 is in San Isidro, located in Starr County, Texas, within the Rio Grande City metro area. Its 2020 Census population was 168. The estimated median adjusted gross income per tax return is $32,143.

2020 Population
168
Census ZCTA
County
Starr
FIPS 48427
Median income (est.)
$32,143
IRS SOI 2022
Land Area
38.928 mi²
+ 0 mi² water

01Location & Geography

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

Primary CitySan Isidro, TX
CountyStarr County (FIPS 48427)
StateTexas (FIPS 48)
Metro Area (MSA)Rio Grande City, TX Micro Area (40100)
Census Region / DivisionSouth Region · West South Central Division
Coordinates26.737864, -98.39721
Land / Water Area38.928 mi² land · 0 mi² water

02Income & Economics

Distribution of the 140 individual tax returns filed in 78588 by adjusted gross income bracket (IRS SOI, 2022).

< $25K
35.7%
$25K–$50K
50.0%
$50K–$75K
0.0%
$75K–$100K
14.3%
$100K–$200K
0.0%
$200K+
0.0%
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 78588's IRS income metrics, 2020–2022.

Median income (2021→2022)
$32,143
▲ 10.2%
Filers earning $200K+
0.0%
▲ 0.0 pt
Total filers
140
▲ 0.0%
GET /zipc/v2/zipcodes/78588/soi?year=… $27K 2020 $29K 2021 $32K 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 78588 ZCTA.

2000
180
 
2010
238
▲ +32.2%
2020
168
▼ -29.4%

05USPS Postal Details

Delivery and facility attributes from the monthly USPS dataset.

ZIP ClassificationNon-Unique Zip
Facility TypePost Office
Carrier Route SortC
USPS Finance Number488060
City AliasesSan Isidro

06Frequently Asked Questions

What county is ZIP code 78588 in?

ZIP code 78588 is in Starr County, Texas (county FIPS code 48427).

What city is ZIP code 78588?

The primary USPS city for 78588 is San Isidro, TX.

What metro area (MSA) is 78588 in?

78588 is part of the Rio Grande City, TX Micro Area (MSA code 40100).

What is the population of ZIP code 78588?

The 2020 Census population of 78588 was 168 residents.

What is the median income in ZIP code 78588?

Based on IRS Statistics of Income data, the estimated median adjusted gross income per tax return in 78588 is about $32,143. Note that adjusted gross income is a tax measure and differs from U.S. Census household income.