Q. After laicization, what powers does a priest still have? In an emergency, for example, can he validly hear confession? And is it possible for him to be restored?
A. Here is a reply from Father Francis Hoffman, J.C.D:
Once a priest, always a priest: the Sacrament of Holy Orders imprints an indelible character on the soul of the priest that empowers him to confect the sacraments. However, if a priest has been laicized, which is to say, returned to the lay state, he may no longer dress as a priest or function as a priest. He is not allowed to celebrate the sacraments, but he would be allowed to receive the sacraments.
If he were to come across a person in danger of death, he would still have the power to forgive sins through sacramental absolution, and in such a case he would be allowed to do so.
Laicization can be either voluntary as a favor, or involuntary as a punishment. In either case, the man is no longer allowed to carry out the sacramental duties of an ordained cleric with that one exception: in danger of death he can hear a person’s confession (see Canons 976, 986.2, 1335).
Finally, it is possible for a laicized priest to be restored to holy orders, but only by express rescript from the pope (see Canon 293).