Eucharistic Ministers serve as extraordinary (outside the ordinary) ministers in the celebration of the Eucharist by assisting the priests in the distribution of the Body and Blood of Christ when there is a need. The ministers are trained in the rubrics of the Mass and are directed by the parish priests of any liturgical changes affecting the distribution of the Eucharist.

The proof of his boundless charity that Christ the Lord left to his Bride the Church, namely, the inexpressible and supreme gift of the Eucharist, requires us to deepen our appreciation of this great mystery and to share ever more fully in its saving power....

The new conditions of the present seem to demand that, without prejudice to the supreme reverence due to so great a sacrament, access to communion be made easier, so that by sharing more fully in the effects of the sacrifice of the Mass, the faithful may more willingly and intensely give themselves to God and to the good of the Church and of all humanity.

Immensae Caritatis, Introduction.I