53 Pa. Stat. § 30566
Any contributor who is entitled to retire under the provisions of this act by reason of having completed twenty-five years of total service or by reason of having reached superannuation retirement age may file with the retirement board a written application for retirement in the form required for such application, but requesting that such retirement shall become effective as of the time of his death, electing one of the options provided in section 12 and nominating a beneficiary under said option as required in said section.
In all such cases, the application shall be held by the retirement board until the contributor shall file a later application in the usual manner for retirement or until the death of the contributor occurring while in city service, at which time his retirement shall become effective with the same benefits to the designated beneficiary as if the contributor had retired on the day immediately preceding his death.
53 P.S. § 30566