78321 ZIP Code: Elgin, Texas
Official postal information, geographic coordinates, USPS post office locations, and US Census Bureau demographic metrics for postal code 78321 in Elgin, TX.
Postal & Geographic Specifications USPS Data
Demographic & Economic Profile (US Census Bureau)
American Community Survey (ACS) 5-Year Verified Metrics
Editor's Neighborhood Insight & Local Context
78321 is an active postal delivery zone serving Bay City in Matagorda County, Texas. Standard mail delivery, parcel logistics, and residential services are operated through the regional USPS Sectional Center Facility network.
Designated USPS Post Office Facility Mail & Parcel Drop-off
Mon-Fri 8:30 AM - 5:00 PM; Sat 9:00 AM - 1:00 PM; Sun Closed
Geographic Map & Coordinates
29.0000, -103.9000Adjacent & Contiguous ZIP Codes
Nearby postal codes bordering 78321 in Elgin
Frequently Asked Questions About 78321 (Elgin, TX)
What county is ZIP code 78321 located in for tax and voter purposes? ▾
ZIP code 78321 is located within Matagorda County, Texas. The official county seat is Bay City, and the primary jurisdiction carries Texas FIPS code 48321.
What is the 4-digit ZIP+4 code for 78321? ▾
The full 9-digit postal code format is 78321-XXXX, where the last 4 digits specify exact delivery routes, high-rise buildings, or street blocks. For regular mail and parcel shipping, the 5-digit code 78321 is fully valid, while specific ZIP+4 extensions can be verified with USPS address validation.
Where is the nearest USPS post office for 78321 and what are the lobby hours? ▾
The primary USPS facility serving 78321 is USPS Post Office - Bay City, located at 100 Main St, Bay City, TX 78321. Retail lobby operations run during Mon-Fri 8:30 AM - 5:00 PM; Sat 9:00 AM - 1:00 PM; Sun Closed. Contact inquiries can be made at (800) 275-8777.
What telephone area codes and time zone apply to 78321? ▾
ZIP code 78321 is located in the America/Chicago (CST / CDT) time zone (observing Daylight Saving Time). Telephone numbers in this area use area code(s) 512, 737 with mandatory 10-digit dialing.
What is the population and median household income for 78321? ▾
According to U.S. Census Bureau ACS data, ZIP code 78321 in Bay City has an estimated population of 14,502 residents and a median household income of $99,840 per year (compared to the Texas state median of $74,640).
What postal codes border 78321 in Bay City? ▾
Adjacent and contiguous ZIP codes bordering 78321 include 78021 (Bastrop, ~0 mi), 78121 (Denton City 60, ~0 mi), 78221 (Granbury, ~0 mi), 78421 (Stratford, ~0 mi).