This Part IV of this subtitle (Reformed Contributory Pension Benefit) applies to: an individual who becomes a member of the Employees’ Pension System or the Teachers’ Pension System on or after July 1, 2011; and except as provided in § 23–215.1 of this subtitle, a member of the Employees’ Pension System or Teachers’ Pension System who separated from employment on or before June 30, 2011, and subsequently becomes employed in a position eligible for membership in the Employees’ Pension System or the Teachers’ Pension System on or after July 1, 2011. This Part IV does not apply to an employee of: a participating governmental unit that was participating in the Employees’ Pension System prior to July 1, 2011, and that has not elected to participate in the Alternate Contributory Pension Selection under § 31–116.1 of this article; or a former participating governmental unit, other than Frederick County, that has withdrawn from the Employees’ Pension System.