Q. Is it possible to have Confession en masse?
A. It’s possible to receive General Absolution (Confession en masse) when the circumstances permit it. But generally, circumstances do not permit it. This is outlined in the Code of Canon Law, no. 961:
“§1 General absolution, without prior individual confession, cannot be given to a number of penitents together, unless: 1) danger of death threatens and there is not time for the priest or priests to hear the confessions of the individual penitents; 2) there exists a grave necessity, that is, given the number of penitents, there are not enough confessors available properly to hear the individual confessions within an appropriate time, so that without fault of their own the penitents are deprived of the sacramental grace or of holy communion for a lengthy period of time. A sufficient necessity is not, however, considered to exist when confessors cannot be available merely because of a great gathering of penitents, such as can occur on some major feast day or pilgrimage.”
It’s up to the diocesan bishop and the bishops’ conference to determine when the second condition applies. Generally, outside of mission territories, the second condition does not apply at any time in the United States.