4 Pa. Code § 612.11 – Break in service.

(a) Generally. For purposes of seniority, the following shall constitute a break in service:
1. (1) Removal for just cause.
2. (2) Resignation.
3. (3) Retirement.
4. (4) Failure to accept an offer to return after furlough under 71 Pa.C.S. § 2602(b)(1) (relating to furlough) and this subpart.
5. (5) Failure to accept an offer to return after a leave of absence under 71 Pa.C.S. § 2608(b) (relating to leave of absence) and this subpart.
6. (6) Expiration of mandatory, preferred or optional reemployment rights.
7. (7) Failure to report after a leave of absence.
(b) Effect on seniority. If a break in service occurs, the employee shall lose accrued seniority.
(c) Furlough and leave. Periods of furlough and leaves of absence shall be deemed continuous employment for seniority purposes, except that during the period of furlough or leave of absence, the employee shall not accrue credit towards seniority.
(d) Involuntary demotion. A demotion under § 610.31 (relating to voluntary demotion) shall terminate seniority in the job classification from which demoted.