The postulancy lasts about a year. It is a time of discovery of the life of the Brothers of Saint John and of discernment with a view to entering the novitiate. Depending on the country, the postulant may live in a priory or continue to live in his usual place and attend the postulancy meetings regularly.

Welcomed in a priory, the postulant participates in the life of the brothers. They meet regularly with a leader and a spiritual guide of their choice. They also receive an initial formation.

In the non-residential postulancy, postulants follow a programme of monthly meetings and formation in a priory. They are encouraged to visit different priories to get to know the Congregation better in the diversity of its missions and places of life and thus deepen their discernment. They are followed by the brother responsible for the postulancy and by a spiritual guide of their choice. They can then continue their studies or professional activities. Before applying to enter the novitiate, they make a vocational discernment retreat.