In addition to the provisions of subchapter I of this chapter, an employee shall be eligible for the early retirement option provided by this chapter beginning with the month after the employee has terminated employment, if:
(1) The employee has 15 years of credited service under this chapter as of June 30, 1991, exclusive of service credited under § 5501(e)(4), (5) and (12) of this title, and shall have attained age 50 on or before June 30, 1991; or
(2) The employee has 25 years of credited service under this chapter as of June 30, 1991, exclusive of service credited under § 5501(e)(4), (5) and (12) of this title, regardless of age.
(3) In addition to meeting the credited service and age requirements contained in paragraphs (1) and (2) of this section, an employee must meet the requirements for a disability pension contained in § 5524 of this title, and the employee’s termination from employment shall be governed by § 5524(b) of this title.