Post Office - Johnstown 200 N Main St Johnstown, NE 69214 Phone : (402) 722-4438 Business Category Post Offices Toll-Free           (800) ASK-USPS United States Government--johnstown, Post Office Po Box 9998 Johnstown, NE 69214 Phone : (402) 722-4438 United States Government--johnstown, Post Office Business Category Government Offices-Federal Post Offices Government Offices & Public Schools