(a) An employee who has 5 years of credited service, exclusive of service credited under § 5501(e)(4), (5) and (12) of this title, and develops a disability shall become eligible to receive a disability pension beginning with the fourth month following the inception of his or her disability. Such individual shall cease to be eligible at the end of the month in which he or she recovers from disability and is again offered employment as an employee, if such recovery and offer of employment occurs before his or her attainment of age 60.
(b) Such an employee shall be kept on the active payroll and receive credited service from the inception of the employee's disability to the end of the third month following and shall receive payments at the same rate of compensation the employee received before the employee developed a disability.
(c) An employee shall be deemed to have developed a disability for the purposes of this section if the employee has a physical or mental disability which prevents the employee from performing the duties of the employee's position.
(d) An employee who previously elected to participate in the disability insurance option pursuant to § 5519(b)(2) of this title and has been deemed to have a disability pursuant to § 5253(c) of this title and whose benefit under the disability insurance option has been discontinued because of the limits of coverage for mental condition or substance abuse have been exhausted, shall be deemed to have a disability for the purposes of this section and be covered under the disability pension provisions of this section.