California Code, Education Code - EDC § 44927

The governing board of any school district, a county board of education, or the Department of Education may execute a contract with any California teacher-training institution whereby certificated personnel of the school district, county, or the Department of Education may be assigned to the teacher-training institution for full-time or part-time duty for a period not to exceed one year.

Any teacher-training institution in California may execute a contract with the governing board of any school district, a county board of education, or the Board of Education whereby certificated personnel of the institution may be assigned to school districts, county boards of education, or the Department of Education for full-time or part-time duty for a period not to exceed one year.

Any such contract shall provide for the payment, by the entity to which a person is assigned to the employer, of a sum equivalent to the salary and other employment costs of any such employee.  In place of such payment, the contract may provide for the exchange of certificated personnel between the district, county, or Department of Education and the teacher-training institution.  Any such employee shall retain his status as an employee of the school district, county, Department of Education, or teacher-training institution from which he is assigned in all respects during the period of such assignment.