Cal. Educ. Code § 89504
(c) Lump-sum payment for vacation shall not be made to a person who separates from a position for the purpose of accepting another position in the state service, except either of the following:
(2) Upon reassignment of an employee, subsequent to January 1, 1965, from a position other than an academic year position, to an academic year position.
However, a lump-sum payment shall not be made to a person who returns to a position in the same class within 15 working days of the date of the person’s resignation.