Except as provided for in subsection (c)(2) of this section, a former nontemporary State employee who returns to State employment in a position in the State Personnel Management System within 3 years from separation is reinstated. A reinstated State employee shall have unused accumulated sick leave restored. A former nontemporary employee who is reinstated in a position in the State Personnel Management System shall receive credit for time employed before separation for the purpose of determining the employee's: step in the pay grade applicable to the employee's class; rate of annual leave accrual; and seniority rights. A former nontemporary State employee who returns to a position in an independent personnel system in accordance with the reinstatement provisions of that system shall receive benefits allowed by that personnel system.