Approximately 33,000 residents as of recent census estimates.
Retail, healthcare, and light manufacturing, with many residents commuting to Pittsburgh for work. Potential Alternatives If "156421" was a typo, you might be looking for: 15642 : Irwin, PA (the most likely intent). 16421 : A ZIP Code in Erie County, PA . 156421 zip
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 Approximately 33,000 residents as of recent census estimates