Roman Catechism 18.149

Chapter 18 — Part II: The Sacraments — The Holy Eucharist

Section 149. Such at length was the decay of piety that not only was this holy and salutary law unobserved, but Communion was deferred for years. The Council of Lateran, therefore, decreed that all the faithful should receive the sacred body of the Lord, at least once a year, at Easter, and that neglect of this duty should be chastised by exclusion from the society of the faithful.