The current rules for fasting before Communion, introduced by Pope Paul VI on November 21, 1964, are found in Canon 919 of the Code of Canon Law:
- A person who is to receive the Most Holy Eucharist is to abstain for at least one hour before holy communion from any food and drink, except for only water and medicine.
- A priest who celebrates the Most Holy Eucharist two or three times on the same day can take something before the second or third celebration even if there is less than one hour between them.
- The elderly, the infirm, and those who care for them can receive the Most Holy Eucharist even if they have eaten something within the preceding hour.
Regarding point 3, "elderly" is defined as 60 years of age or older. In addition, the Congregation of the Sacraments issued a document, Immensae caritatis, on January 29, 1973, that clarifies the terms of the fast before Communion for "the infirm, and those who care for them":
To give recognition to the dignity of the sacrament and to stir up joy at the coming of the Lord, it is well to observe a period of silence and recollection. It is a sufficient sign of devotion and respect on the part of the sick if they direct their mind for a brief period to this great mystery. The duration of the eucharistic fast, that is, of abstaining from food or alcoholic drink, is reduced to approximately a quarter of an hour for:
- the sick in health-care facilities or at home, even if they are not bedridden;
- the faithful of advanced years, whether they are confined to their homes because of old age or live in homes for the aged;
- sick priests, even if not bedridden, and elderly priests, as regards both celebrating Mass and receiving communion;
- persons caring for, as well as the family and friends of, the sick and elderly who wish to receive communion with them, whenever such persons cannot keep the one-hour fast without inconvenience.
Finally, Catholics are dispensed from all of the rules of fasting before Communion when they are in danger of death.