This section applies only to members of: the Correctional Officers’ Retirement System; the Employees’ Retirement System; the State Police Retirement System; and the Teachers’ Retirement System. This subsection applies to an individual who is a member on or before June 30, 2011. A member may elect to receive a vested allowance if: the member is separated from employment other than by death or retirement; and subject to paragraph (3) of this subsection, the member has at least 5 years of eligibility service. A former member of the State Police Retirement System who separated from employment on or before June 30, 1989, must have at least 15 years of eligibility service to elect a vested allowance. A member is deemed to have elected a vested allowance, unless the member requests the return of the accumulated contributions before membership ends. This subsection applies to an individual who becomes a member on or after July 1, 2011. A member is eligible to receive a vested allowance if: the member separated from employment other than by death or retirement; and the member has at least 10 years of eligibility service. A vested allowance is a deferred allowance starting at: normal retirement age for members of: the Employees’ Retirement System; the State Police Retirement System; and the Teachers’ Retirement System; except as provided in item (3) of this subsection, age 55 for a member of the Correctional Officers’ Retirement System; or age 60 for a member of the Correctional Officers’ Retirement System who: served as a maximum security attendant at the Clifton T. Perkins Hospital Center; separated from employment as a maximum security attendant at the Clifton T. Perkins Hospital Center before July 1, 2016; and does not resume employment in a position eligible for membership in the Correctional Officers’ Retirement System. A vested allowance: is computed as a normal service retirement allowance on the basis of the former member’s creditable service and average final compensation at the time of separation from employment; and may be paid in one of the optional forms of allowances under § 21–403 of this article. If a member separated from employment on or before June 30, 1990, unused sick leave reported by the member’s employer at the time of separation from employment is creditable service for computing the vested allowance. If a former member who elected a vested allowance requests the return of accumulated contributions before payment of the vested allowance begins, the Board of Trustees shall return the accumulated contributions to the former member. When accumulated contributions are returned to a former member, the former member is not entitled to further benefits on account of the former member’s previous membership.