Minn. Stat. § 44.10
Subd. 1. Employees in classified service.
Subd. 2. Police or fire department employees.
Subject to the completion of an existing probationary period, any permanent employee of a police or fire department under the jurisdiction of a police or fire civil service commission at the time of the effective date of a merit system ordinance shall automatically become a permanent employee in the classified service subject to and protected by this chapter without the service of any additional probationary period thereunder for the position then occupied.