What are the Northumberland, Pennsylvania Zip Codes for 2020, 2019Primary Zip Codes for NorthumberlandZip CodePrimary CitySecondary City17857NorthumberlandNorthumberland, Lithia Sprs, Oak Park, Kapp Heights, NorthumberlndCities sharing Zip Codes with NorthumberlandZip CodePrimary CitySecondary CityMore Information17857NorthumberlandNorthumberlnd17857NorthumberlandLithia Sprs17857NorthumberlandOak Park17857NorthumberlandKapp Heights Kapp Heights population stats Advertisements