 After graduating from high school, Hartmayer joined the Order of Friars Minor Conventual, commonly known as the Conventual Franciscans, at the St. Joseph Cupertino Friary in Ellicott City, Maryland.He took his simple vows as a Conventual Franciscan friar on August 15, 1970, before making his solemn profession on August 15, 1973.He also studied at St. Hyacinth College and Seminary in Granby, Massachusetts, where he obtained a Bachelor of Science degree in philosophy in 1974.