160. The Priest then takes the paten or ciborium and approaches the communicants, who usually come up in procession.
It is not permitted for the faithful to take the consecrated Bread or the sacred chalice by themselves and, still less, to hand them on from one to another among themselves. The norm established for the Dioceses of the United States of America is that Holy Communion is to be received standing, unless an individual member of the faithful wishes to receive Communion while kneeling (Congregation for Divine Worship and the Discipline of the Sacraments, Instruction, Redemptionis Sacramentum 91).
When receiving Holy Communion, the communicant bows his or her head before the Sacrament as a gesture of reverence and receives the Body of the Lord from the minister. The consecrated host may be received either on the tongue or in the hand, at the discretion of each communicant. When Holy Communion is received under both kinds, the sign of reverence is also made before receiving the Precious Blood.
161. If Communion is given only under the species of bread, the Priest raises the host slightly and shows it to each, saying, The Body of Christ. The communicant replies, Amen, and receives the Sacrament either on the tongue or, where this is allowed, in the hand, the choice lying with the communicant. As soon as the communicant receives the host, he or she consumes the whole of it.
If, however, Communion is given under both kinds, the rite prescribed in nos. 284-287 is to be followed.
162. In the distribution of Communion the Priest may be assisted by other Priests who happen to be present. If such Priests are not present and there is a truly large number of communicants, the Priest may call upon extraordinary ministers to assist him, that is, duly instituted acolytes or even other faithful who have been duly deputed for this purpose.[Cf. Inaestimabile Donum 10; Ecclesiae de Mysterio 8] In case of necessity, the Priest may depute suitable faithful for this single occasion.[Cf. Roman Missal, Appendix III, Rite of Deputing a Minister to Distribute Holy Communion on a Single Occasion]
These ministers should not approach the altar before the Priest has received Communion, and they are always to receive from the hands of the Priest Celebrant the vessel containing the species of the Most Holy Eucharist for distribution to the faithful.
There’s a lot of fuss and ink spent on lay people serving as Communion ministers. I don’t really see the point of most of it. GIRM 17-20 has already laid down the principle that a full inner and outer participation best serves the liturgy and its spiritual fruitfulness. More involvement, generally speaking, is better than less. The whole notion of fewer lay ministers actually goes against the grain of the Roman Rite, though I can understand the alarm it might foster in priest-centered communities like Vatican City.
That said, I have no problem with priests taking on their ordinary role at Mass. Even when they don’t call in ahead of time and inform they will or won’t be participating outside of concelebration. My own sense is that some clergy take their role as ordinary Communion minister less seriously, and why not–it’s only a part of how they serve the liturgy.
I’ll leave off the commentary with the thought that these sections are probably more detailed than they need to be. I think the role of the presider and deacon, not to mention concelebrating clergy can be underscored without a uniform legislation. But what’s written here is not really burdensome.