The 1983 Code of Canon Law attaches the penalty of (automatic excommunication) to the following actions:
- Apostates, heretics, and schismatics (can. 1364)
- Desecration of the Eucharist (can. 1367)
- A person who physically attacks the pope (can. 1370)
- A priest who in confession absolves a partner with whom they have violated the sixth commandment (can. 977, can. 1378)
- A bishop who consecrates another bishop without papal mandate (can. 1382) An example of this would be the case of Archbishop Marcel Lefebvre who was excommunicated in 1988. The excommunication was lifted in 2009 in anticipation of a reconciliation (which did not occur).[15]
- A priest who violates the seal of the confessional (can. 1388)
- A person who procures an abortion (can. 1398)
- Accomplices who were needed to commit an action that has an automatic excommunication penalty (can. 1329)
Generally speaking, automatic excommunications are not known to the public. Unless the individual committed the action in a public manner that would cause the local ordinary to issue a statement about the automatic excommunication, the burden is on the offender to confess the sin and seek the removal of the penalty.