Make a Sign of Reverence
As the communicant in front of you receives Holy Communion, you are to make a sign of reverence. The Bishops of the United States have decided that this sign of reverence is to be a bow. You then approach the Priest, Deacon, or Extraordinary Minister of Holy Communion (hereinafter Priest) with hands extended. The Priest then lifts the Sacred Host, shows it to the communicant, and says, “The Body of Christ.” The communicant says, “Amen.” If one receives on the tongue, the communicant approaches the Priest who lifts the Host and shows it to the communicant and says, “The Body of Christ.” The communicant then says, “Amen,” opens his/her mouth, and extends his/her tongue (Please be sure to hold still until after the Host is placed on your tongue!).

Please Do Not Move
After bowing as a sign of reverence, whether you receive on the tongue or the hand -- DO NOT MOVE -- until the Priest has placed the Sacred Host on your tongue or hand and removed his hand.

If One Receives on the Hand
Unless arthritis hinders one, hold your top hand flat. And do not move until the Priest has placed the Sacred Host on your hand and removed his. Do not move your hand, arms, fingers, etc. If Your Hand/Hands are Impeded Never receive Holy Communion in the hand when your hands are impeded; e.g., carrying a cane or some other walking-assistance device, carrying a child in your arms, carrying a purse, having a tissue or handkerchief in your hand, have a cast on your hand, etc. Never receive Holy Communion by extending only one hand. Never reach and grab the Host.

If One Receives on the Tongue
Open your mouth wide, stick out your tongue, and hold still (see detailed instructions below). Please do not move your neck, head, tongue, mouth, or body. Hold still, and do not move until the Priest has placed the Host on your tongue and removed his hand; otherwise, you may get the Host on the nose, on the teeth, or who knows where. Please do not lick the Priest’s hand - just hold still, and all will be well!

Children
Make sure you hold your hands up high so the Priest can reach your hands. Parents, please instruct your children accordingly.

Consuming The Body of Christ
Once you have received the Sacred Host (after the Priest has moved his hand), consume the Host immediately and directly in front of the Priest and then reverently move on --do not step aside and bless yourself, genuflect, etc.

The Posture
The faithful are not permitted to take the consecrated Host by themselves. The norm for reception of Holy Communion in the United States is standing. However, we will not deny Holy Communion to people who choose to kneel.

Tongue or Hand?
There is nothing intrinsically more reverent about reception on the tongue or less reverent about receiving in the hand. Reverence or irreverence are generally determined by other factors: the spiritual attitude of the recipient, the demeanor of the one giving communion, the adequacy of Eucharistic understanding, and the manner in which the Eucharistic elements are treated both within and outside Mass. Instructions on Receiving Holy Communion with Proper Reverence

Hand
St. Cyril of Jerusalem in the fourth century offered a beautiful and powerful catechesis on the mode of receiving communion in the hand that is still applicable today: "When you approach, do not go stretching out your open hands or having your fingers spread out, but make the left hand into a throne for the right which shall receive the King, and then cup your open hand and the Body of Christ, reciting the 'Amen.' Then sanctify with all care your eyes by touching the Sacred Body, and receive it. But be careful that no particles fall, for what you lose would be to you as if you had lost some of your members. Tell me, if anybody had given you gold dust, would you not hold fast to it with all care and watch lest some of it fall and be lost to you? Must you not then be even more careful with that which is more precious than gold and diamonds so that no particles are lost?"

Tongue
If you choose to receive on the tongue, great! This has been the centuries-old custom of our ancestors. The contemporary church offers little instruction in this area, so here is some advice. You should practice in a mirror. It’s really very simple – while your mouth is closed, make sure your tongue is touching the inside of your lower lip. Then, maintaining this tongue position, open your mouth as wide as you can by lowering your lower jaw. Your mouth and tongue are then in the correct position for the Priest to place the Host on your tongue.

Not all bishops' conferences have requested permission to allow people to receive communion in the hand, and the traveling Catholic should be ready to adapt to local customs with respect to posture and mode of receiving Communion.

The Church's official Regulations
From the General Instruction of the Roman Missal

#160. The priest then takes the paten or ciborium and goes to the communicants, who, as a rule, approach in a procession.

The faithful are not permitted to take the consecrated bread or the sacred chalice by themselves and, still less, to hand them from one to another. The norm for reception of Holy Communion in the dioceses of the United States is standing. Communicants should not be denied Holy Communion because they kneel.

When receiving Holy Communion, the communicant bows his or her head before the Sacrament as a gesture of reverence and receives the Body of the Lord from the minister. The consecrated host may be received either on the tongue or in the hand, at the discretion of each communicant. When Holy Communion is received under both kinds, the sign of reverence is also made before receiving the Precious Blood.

#161. If Communion is given only under the species of bread, the priest raises the host slightly and shows it to each, saying, Corpus Christi (The Body of Christ). The communicant replies, Amen, and receives the Sacrament either on the tongue or, where this is allowed and if the communicant so chooses, in the hand. As soon as the communicant receives the host, he or she consumes it entirely.