Voluntary retirement is when an employee wants to retire voluntarily before their superannuation date. In this case, the retirement benefit may be deferred to the date of superannuation. The settlement amount in such cases is calculated based on the size of the accumulated corpus and the number of years of work. Voluntary retirement rules are defined under Rule 12 of the Central Civil Services (Implementation of NPS) Rules, 2021, for government employees covered under the National Pension System (NPS). According to this rule, "At any time after a Subscriber has completed twenty years' regular service, he may, by giving notice of not less than three months in writing to the appointing authority, retire from service."