On [[February 15]], 2004, Fr. Thomas was elevated to the rank of [[archimandrite]] by Bp. Antoun, and on [[December 5]], 2004, he was consecrated to the [[bishop|episcopacy]] by [[Patriarch]] [[Ignatius IV (Hazim) of Antioch]] in Damascus, Syria.
Bp. Thomas was enthroned as Bishop of Oakland and the East at St. George Cathedral in Pittsburgh (Borough of Oakland), Pennsylvania, on [[May 6]], 2005. In August of 2006, Bishop Thomas was awarded a Doctorate in Education from California Coast University. His Grace also sits on the editorial board of ''Christian Bioethics''. In 2006, the Church of St. George in Charleston, West Virginia, purchased a chancery for the diocese, and in October of that year was elevated to a cathedral, thus adding another see to Bp. Thomas's diocese and renaming it to the ''Diocese of Charleston, Oakland and the Mid-Atlantic''.
His Grace's residence is at the diocesan chancery in Charleston.