Does someone who is excommunicated cease being Catholic or are they simply cut off from the benefits of being Catholic?
To be excommunicated is to remain a Catholic, but a Catholic for whom active participation in the sacramental life of the Church is denied until such time as the person repents and receives absolution. If the person is a priest he may not celebrate the sacraments or preach or publicly represent the Church in any way. (Canon 1331)
Fr. Vincent Serpa, O.P.