The main focus of John's career was with Fairfax County Public Schools, for 38 years.  Most of his time was spent in the General Services Department holding many positions in the Inventory Operations and Procurement Branches.  In 1993 John was promoted to the position of Coordinator/Director of the Logistical Services Office in the Department of Facilities Services until his retirement in February 2005.

In 1996 John established Armentrout Enterprises Network (AENetwork.com) as a result of a need to place his local Babe Ruth League on the Internet.  To this day, AENetwork is an ongoing business specializing in youth sports organizations.  John manages websites in Virginia, South Carolina, Tennessee, Georgia, Florida, North Carolina, Alabama, and Louisiana.  In addition, he manages the websites for the Babe Ruth Southeast, Southwest and Midwest Plains Regions, and a number of commercial sites.

Volunteer work is with the Babe Ruth Southeast Region as the Assistant Commissioner, Operations.  John has been continually associated with Babe Ruth League, Inc. for over 34 years.