Foster opened his first dojo in the U.S. in the mid-sixties at Tampa, Florida. Beginning in 1967, he established accredited Yoshukai Karate programs in Florida colleges and universities including St. Leo College, Florida State University, University of South Florida, University of Tampa and Florida Atlantic University. From Tampa he moved to Orlando, Florida, where he kept a dojo during the early seventies. During the late seventies and eighties Foster maintained a dojo in Daytona, Florida. In the early nineties he relocated to Titusville, Florida, where he shared a hombu dojo (headquarters) for seven years with Aikido Sensei Tom Walker. Foster continued to instruct senior grades at his hombu dojo in Titusville until 2008, when he retired from active teaching due to health reasons.