§1. A religious must be held as dismissed ipso facto from an institute who: 1) has defected notoriously from the Catholic faith; 2) has contracted marriage or attempted it, even only civilly; 3) has been illegitimately absent from the religious house, pursuant to can. 665 §2, for 12 consecutive months, taking into account that the location of the religious himself or herself may be unknown.
§2. In such cases the Major Superior, with his or her Council and without hesitation, having gathered the evidence, must issue the statement of the case so that the dismissal may be juridically constituted.
§3. In the case envisaged by §1 n. 3, in order to be juridically constituted, this statement must be confirmed by the Holy See; for institutes of diocesan right the confirmation rests with the Bishop of the principal See.
Source: Code of Canon Law (Vatican.va)