(a) A leave of absence with pay authorized by an employer is not considered as interrupting employment. If the employee is a permanent part-time employee, credited service shall be granted on a basis proportionate to that which would have been earned as a permanent full-time employee.

(b) A leave or leaves of absence without pay exceeding 10 accumulated working days in any calendar year or layoff status authorized by an employer shall be considered as an interruption of employment and credited service may not be granted.

(c) Notwithstanding (b) of this section, an employee who takes more than 10 days leave of absence without pay in a calendar year because the employee is unable to work due to an on-the-job injury or occupational illness for which the employee is receiving benefits under AS 23.30 may elect to receive credited service for the time on leave of absence without pay status. When an employee elects to receive credited service under this subsection, an indebtedness is established. The amount of the indebtedness is equal to the contributions that the employee would have made if the employee had been working, less the sum of contributions that the employee made for those periods of time and an amount equal to contributions that would have been made for the first 10 days of leave without pay. Interest as prescribed by regulation accrues on the indebtedness beginning on the date that the employee returns to work or terminates employment. If there is an outstanding indebtedness at the time the employee is appointed to retirement, benefits shall be actuarially adjusted.

(d) An employee of a school district, a regional educational attendance area, or a state boarding school who is assaulted while on the job and who, as a result of a physical injury from the assault, is placed on leave without pay, whether or not the employee receives workers' compensation benefits under AS 23.30 for the injury, is entitled to accrue credited service while the employee, because of the injury, is on leave-without-pay status or is receiving the benefits under AS 23.30. Entitlement to credited service under this subsection ends when the employee is eligible to receive benefits under AS 39.35.370(a) or 39.35.410(a).