In the Archdiocese of Baltimore at the present time, there are no generally accepted cases in which the conditions warranting the imparting of general absolution would be foreseen to exist. Should a confessor believe that such conditions exist in individual cases, he is required to obtain prior permission of the diocesan bishop.
The revised Code of Canon Law specifies the conditions under which general absolution may be imparted. Canon 961, §1, 1º, 2º states:
§1 Absolution cannot be imparted in a general manner to a number of penitents at once without previous individual confession unless:
1º the danger of death is imminent and there is not time for the priest or priests to hear the confessions of the individual penitents;
2º a serious necessity exists, that is, when in light of the number of penitents a supply of confessors is not readily available rightly to hear the confessions of individuals within a suitable time so that the penitents are forced to be deprived of sacramental grace or holy communion for a long time  through no fault of their own; it is not considered a sufficient necessity if confessors cannot be readily available only because of the great number of penitents as can occur on the occasion of some great feast or pilgrimage.
(See also Rite of Penance #60).
The United States Conference of Catholic Bishops has determined that the word diu (“for a long time”) in Canon 961, §1,2º should be understood as “a month.”