Like all the sacraments the Anointing of the Sick is a liturgical and communal celebration, whether it takes place in the family home, a hospital or church, for a single sick person or a whole group of sick persons. It is very fitting to celebrate it within the Eucharist, the memorial of the Lord's Passover. If circumstances suggest it, the celebration of the sacrament can be preceded by the sacrament of Penance and followed by the sacrament of the Eucharist. As the sacrament of Christ's Passover the Eucharist should always be the last sacrament of the earthly journey, the "viaticum" for "passing over" to eternal life.
Source: Catechism of the Catholic Church (Vatican.va)