If you miss part of the Mass, can you still receive? If you miss the readings and the Gospel? If you come in just before Consecration? If you arrive during the Lamb of God? Where would the line be drawn, if at all? Thanks.
Theoretically speaking, you could enter as the Communion line is queuing up, receive, and leave. This is neither encouraged nor advisable; the point is that there is no “cut-off” point after which you may not receive Communion at that Mass. This presumes that you have not already received Communion that day. If you have already received Communion during that day, to receive again you must either participate in a Mass or be in danger of death. To receive Communion a third time within the same day, you must be in danger of death. Please see the following canons from the Code of Canon Law:
“One who has received the blessed Eucharist may receive it again on the same day only within a eucharistic celebration in which that person participates, without prejudice to the provision of can. 921 §2” (canon 917).
“It is most strongly recommended that the faithful receive holy Communion in the course of a eucharistic celebration. If, however, for good reason they ask for it apart from the Mass, it is to be administered to them, observing the liturgical rites”
"§1 Christ’s faithful who are in danger of death, from whatever cause, are to be strengthened by holy Communion as viaticum.
“§2 Even if they have already received holy Communion that same day, it is nevertheless strongly suggested that in danger of death they should communicate again” (canon 921).