Anointing of the sick, which was formally known as Extreme Unction, is the final sacrament. It is intended to provide spiritual healing and help Catholics transition into the afterlife. Consequently, it is primarily associated with death. While Catholics should receive this sacrament before dying, they also may want to consider taking advantage of it during other times of sickness. Catholics that are very ill (regardless of age), elderly, frail, or facing surgery should consider requesting this sacrament. Catholics are entitled to receive this sacrament any number of times throughout their lives.
References: The Everything Catholicism Book by Helen Keeler and Susan Grimbly