§1. The pastor, parochial vicars, chaplains, and, with regard to all those dwelling in the house, the superior of a community in clerical religious institutes and societies of apostolic life have the duty and right of bringing the Most Holy Eucharist as Viaticum to the sick.
§2. In the case of necessity or with at least the presumed permission of the pastor, chaplain, or superior, who must be notified afterwards, any priest or other minister of holy communion must do this.
Source: Code of Canon Law (Vatican.va)