People who have already been baptized at another Christian church must undertake a different kind of preparation for the Sacraments of Initiation. The Church may insist on separation of these people from the catechumens. The needs of mature, practicing Christians from other faith traditions are considered on an individual basis. Those who have lived as Christians and who only need instruction in the Catholic tradition do not undergo the full program required by catechumens. The parish may propose a period of individual instruction or create a program based on the degree of their familiarity with Christian doctrine.

Christians from other religious backgrounds who want to convert are called candidates. Since candidates are already baptized, the liturgical rites that mark the steps of the formation process are different from those of catechumens. Their journey begins with rites of welcoming by the parish community and recognition by the bishop. Rather than the Rite of Acceptance, they undergo a sacrament of Penance (confession). Like catechumens, candidates undergo a period of training and inquiry, joining services for the Liturgy of the Word. On the first Sunday in Lent, when catechumens are undergoing the Rite of Election, the candidates participate in the Celebration of the Call to Continuing Conversion.

During the period of purification and enlightenment, candidates are expected to participate in a penitential rite as well as a period of reflection. Since candidates will have committed sins since their baptism, they must confess their mortal sins before receiving Confirmation. Reception into full communion in the Catholic Church takes place with the profession of faith, Confirmation, and Eucharist. However, the candidates are not normally admitted to Church life on Holy Saturday. Their first communion will be in a Sunday Eucharist with their local parish.