Redemption is a practice within the Republic of Gilead, in which Handmaids convicted of crimes (such as Gender Treachery) are forced to undergo a clitoridectomy (removal of the clitoris), also referred to as circumcision. It is used as an alternate punishment for Handmaids whom "God has seen fit to make[...]fertile", rather than execution, which is considered 'wasteful'.
The punishment prevents Handmaids from experiencing sexual pleasure (or makes it more difficult at the least) whilst keeping their reproductive organs intact; thus preventing or discouraging Handmaids from committing the 'sin' of fornication or Gender Treachery. Aunt Lydia specifically states the circumcision is intended to 'help' the Handmaid stop wanting "what she cannot have".
The only known instance of this occurs in the television adaption, when Ofglen is found guilty of Gender Treachery with a Martha. Because she is still capable of bearing children, she is sentenced to Redemption, whilst her lover is sentenced to death. The redemption is carried out in a medical clinic, with Ofglen only realising what has been done to her when she wakes up following the operation and finds her groin heavily bandaged[1].
Redemption is only featured in the television adaption; it is unknown if the punishment also exists within the novel.