Catechism of the Catholic Church §1022 — excerpt
Each man receives his eternal retribution in his immortal soul at the very moment of his death, in a particular judgment that refers his life to Christ: either entrance into the blessedness of heaven-through a purification or immediately,-or immediate and everlasting damnation.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: Council of Lyons II (1274): DS 857-858 · Council of Florence (1439): DS 1304- 1306 · Council of Trent (1563): DS 1820 · Benedict XII, Benedictus Deus (1336): DS 1000-1001 · John XXII, Ne super his (1334): DS 990 · Benedict XII, Benedictus Deus (1336): DS 1002 · St. John of the Cross, Dichos 64