Can. 889
§1 Every baptized person who is not confirmed, and only such a person, is capable of receiving confirmation.
§2 Apart from the danger of death, to receive confirmation lawfully a person who has the use of reason must be suitably instructed, properly disposed and able to renew the baptismal promises.

Can. 890 The faithful are bound to receive this sacrament at the proper time. Parents and pastors of souls, especially parish priests, are to see that the faithful are properly instructed to receive the sacrament and come to it at the opportune time.

Can. 891 The sacrament of confirmation is to be conferred on the faithful at about the age of discretion, unless the Episcopal Conference has decided on a different age, or there is a danger of death or, in the judgment of the minister, a grave reason suggests otherwise.

Can. 892 As far as possible the person to be confirmed is to have a sponsor. The sponsor's function is to take care that the person confirmed behaves as a true witness of Christ and faithfully fulfils the duties inherent in this sacrament.