156421 Zip May 2026

The 15642 ZIP Code serves Irwin, North Huntingdon, and portions of Penn Township in Pennsylvania. It is located approximately 20 miles southeast of Pittsburgh. Community & Infrastructure Irwin County: Westmoreland County

15642 is a valid ZIP Code for , and areas in Westmoreland County . However, 156421 is a 6-digit number and does not exist as a standard 5-digit United States ZIP Code. 156421 zip

💡 : U.S. ZIP Codes are always 5 digits in their basic form; the expanded ZIP+4 system uses 9 digits . The 15642 ZIP Code serves Irwin, North Huntingdon,

: A full 9-digit code like 15642-1XXX , where the "1" is the start of the four-digit extension used for more precise mail sorting. However, 156421 is a 6-digit number and does

A mix of historic borough residential areas and suburban developments.

If you are looking for information about the 5-digit ZIP Code , 15642 ZIP Code: Irwin, PA

Most students in this ZIP Code attend the Norwin School District . Demographics & Economy