From a reader:
The seminarians of ___ are assigned a parish for the summer (as most are, I presume). Sometimes the seminarians serve at more than two Masses. Can they receive Holy Communion more than twice?
No. Unless they are about to die, they may receive twice only during one day.
Not only can seminarians receive twice in one day, everyone who is Catholic and in the state of grace can receive twice in one day.
The 1983 Code of Canon Law says:
Can. 917 – Qui sanctissimam Eucharistiam iam recepit, potest eam iterum eadem die suscipere solummodo intra eucharisticam celebrationem cui participat, salvo praescripto Can. 921, § 2.
Someone who has already received the Most Holy Eucharist can receive it again (iterum) on the same day only within the Eucharistic celebration [i.e. Mass] in which the person participates, with due regard for the prescription of can. 921 § 2.
Can. 921 § 2 says that if a person is in danger of death, he may receive Communion even it is not in the context of Mass. That is Viaticum.
That iterum does not mean “again and again”, but merely “again, one more time”.
Also, that “Eucharistic celebration” in the canon does not mean just any service involving Communion. It means Mass. That was cleared up by the Holy See in an official response to a dubium.
So, say in the morning you attend a Novus Ordo Communion service wherein you receive Communion, or you went to a Mass in either Form. Later in the day you stumble into a church where Mass about to be celebrated and decided to stay for it. At that Mass you can receive Communion again (iterum). This would be even if you were, say, visiting a Maronite Catholic Church, or a Ukrainian Catholic Church and their Divine Liturgy was about to get under way.
However, if you were at Holy Mass in the morning and then stumbled into a Communion service at a priest-less parish in the afternoon, you could NOT receive again because a Communion Service isn’t Mass. If you were at Mass in the morning and then in the afternoon when you were visiting your auntie in the hospital when the chaplain came, you could not receive even if the priest invited you to do so (which in my opinion he should not). However, if you stayed for another Mass immediately following, you would not be able to receive.
Canon 917 tries to walk the line between promoting frequent reception of the Eucharist and a superstitious or excessive frequency, which – I can assure you – some people fall into.
The key here is that the second time must be during a Mass, and you may not enter the Mass at some late point merely in order to receive.
And the issue of Viaticum, Communion for someone in danger of death, is a separate issue.