 According to Bishop Thomas J. Paprocki, "excommunication does not expel the person from the Catholic Church, but simply forbids the excommunicated person from engaging in certain activities..." 
These activities are listed in Canon 1331 §1, and prohibit the individual from any ministerial participation in celebrating the sacrifice of the Eucharist or any other ceremonies of worship; celebrating or receiving the sacraments; or exercising any ecclesiastical offices, ministries, or functions.Under current Catholic canon law, excommunicates remain bound by ecclesiastical obligations such as attending Mass, even though they are barred from receiving the Eucharist and from taking an active part in the liturgy (reading, bringing the offerings, etc.).