People are admitted solely based upon the jurisdiction's practice and traditions/interretation of the cnons of the church. It is usually agreed that if a heterodox (non-Orthodox) Christian is admitted by chrismation alone, it is an extension of the principal of "Economia" to that person and an interpretation of the canon of the Church that allows heretics who have left the faith to be chrismated upon their return to the Orthodox Faith. Due to the radical departures in recent years of the heterodox from the faith (i.e. the Episcopalian denial of the Virgin Birth and the physical resurrection of Christ, the Roman Catholics promulgation of non-Orthodox beliefs about the Blessed Theotokos, the Protestant departure of even some of the most basic tenets of th baptism by baptising using the inclusive language in the name of the Parent, Child, and holy spirit orthodox faith, etc) the bishops from some jurisdictions in the United States or the West have declined to use economia allow chrismation alone. Usually the Greek Orthodox Church, Antiochian Orthodox Church, russian Orthodox Patrirchate, and most of the OCA allow admission to the faith by Chrismation, some ROcor Bishops also allow this. Most Old Calendar and some ROCOR Churches require rebaptism (they actually view it as a first baptism, not recognizng the heterodox baptism due to baptisal form or formula issues).