ZIP Code 15666

15666 is one of Pennsylvania's ZIP codes, delivering to addresses in Mount Pleasant, Westmoreland County.

City: Mount Pleasant
County: Westmoreland County
State: Pennsylvania
Prefix: 156xx

Where this code sits

15666 is part of the 156xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Mount Pleasant.

Mount Pleasant Pennsylvania ZIP codes →

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 15666 delivers to without sharing its boundary.

ZIP codes nearest 15666

The ZIP codes whose reference points sit closest to 15666.
ZIP code	Distance	Delivers to
ZIP code 15621	2.9 mi	Calumet, PA
ZIP code 15674	3.2 mi	Norvelt, PA
ZIP code 15689	3.3 mi	United, PA
ZIP code 15688	3.8 mi	Tarrs, PA
ZIP code 15616	4.0 mi	Armbrust, PA
ZIP code 15639	4.6 mi	Hunker, PA
ZIP code 15612	5.2 mi	Alverton, PA
ZIP code 15676	5.7 mi	Pleasant Unity, PA

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 15666, plotted from its record coordinates.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope ZIP code 15666. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.