Congregation for Divine Worship and the Discipline of the Sacraments, Response Concerning the Manner of Receiving Holy Communion, 1999.
Whether in dioceses where it is allowed to distribute Communion in the hands of the faithful, a priest or extraordinary ministers of Holy Communion may restrict communicants to receive Communion only in their hands, not on the tongue.
Response. Certainly it is clear from the very documents of the Holy See that in dioceses where the Eucharistic bread is put in the hands of the faithful, the right to receive the Eucharistic bread on the tongue still remains intact to the faithful. Therefore, those who restrict communicants to receive Holy Communion only on in the hands are acting against the norms, as are those who refuse to Christ’s faithful [the right] to receive Communion in the hand in dioceses that enjoy this indult.
With attention to the norms concerning the distribution of Holy Communion, ordinary and extraordinary ministers should take care in a particular way that the host is consumed at once by Christ’s faithful, so that no one goes away with the Eucharistic species in his hand.
However, let all remember that the time-honored tradition is to receive the host on the tongue. The celebrant priest, if there is a present danger of sacrilege, should not give the faithful communion in the hand, and he should make them aware of the reason for way of proceeding.
Notitiae 35 (1999): 160-161. http://www.adoremus.org/0203CommunionHand.html