IF YOU HAVE BEEN BAPTIZED
If a Christian who has been baptized in another denomination wishes, of his or her own free will, to join the Catholic Church, he or she can contact the parish priest of the Catholic parish in their area. If the initial discussion suggests a reason to proceed, a period of exploration lasting about a year typically begins.
The purpose of this exploration period is for the individual to become familiar with the life of the Church—especially their parish and diocese—by participating in its activities and gaining foundational knowledge about the Catholic faith and worldview. In some locations, this process involves a year-long course, which can also be attended without a firm intention of joining the Catholic Church.
After the year of exploration, a decision can be made about whether to become a member of the Church. The parish priest will present the matter to the bishop, who formally welcomes the new member into full communion with the Church and typically administers the Sacrament of Confirmation at the same time.
IF YOU HAVE NOT BEEN BAPTIZED
If an unbaptized adult or young adult wishes to become a Christian and a member of the Catholic Church, he or she can contact the parish priest of the Catholic parish in their area. The parish priest will provide guidance on how catechesis (preparation for baptism), also known as the catechumenate, will be arranged in this specific case. If possible, adults are usually baptized during the Easter Vigil, at which time they also receive the Sacrament of Confirmation and Holy Communion for the first time.