In 1967 he joined the staff of the state hospital in Lincoln, Nebraska, where he served as director of psychology in addition to clinical and administrative roles. He was a member of the founding board of the Lincoln Samaritan Counseling Center and served as a counselor and interim director there. President of Zeisset Associates, Inc., a personality-type training company, he co-developed one of the early Myers-Briggs Type Indicator® certification programs and developed the first curriculum materials on statistics and measurement oriented specifically for training MBTI® practitioners.