The ancient catechumenate was formally revived after the Second Vatican Council, but the revival itself produced something specific. The council's 1963 constitution on the liturgy, Sacrosanctum Concilium, called explicitly for the restoration of a staged adult catechumenate, and the Congregation for Divine Worship answered with a specific rite, the Ordo Initiationis Christianae Adultorum, promulgated in 1972 and known in English as the Rite of Christian Initiation of Adults.
The rite is not a single ceremony but a defined sequence of four periods separated by three ritual thresholds. Inquiry, sometimes called the precatechumenate, is an unstructured period of first contact with the community. The Rite of Acceptance into the Order of Catechumens marks the formal beginning of the catechumenate proper, a period of instruction and gradual formation that can last a year or more. The Rite of Election, typically celebrated at the start of Lent, enrolls the candidate's name and opens the period of purification and enlightenment, an intense final stretch of prayer, scrutiny and preparation running through Lent itself. Initiation follows at the Easter Vigil, where baptism, confirmation and first communion are usually celebrated together, and a final period called mystagogy continues the newly initiated person's formation through the Easter season.
The structure is deliberately built on the ancient model rather than invented new, restoring stages the early church observed and naming them for a modern congregation.