The Sacrament of Holy Order is the continuation of Christ's priesthood, which He bestowed upon His Apostles; thus, the Catechism of the Catholic Church refers to the Sacrament of Holy Order as "the Sacrament of Apostolic Ministry."
In the Sacrament of Holy Order, a man is incorporated into the priesthood of Christ at one of three levels: the episcopate, the priesthood, or the diaconate.
The Sacrament of Holy Order can be validly conferred only on baptized men, following the example set by Christ and His Apostles, who chose only men as their successors and collaborators. A man cannot demand ordination; the Church has the authority to determine eligibility for the Sacrament. If you are a baptized Catholic man and you think you might be called to priesthood, please contact the Archdiocese of San Francisco's Vocation Office: (415) 614-5500 or visit the Vocation MinistryWebsite.