California Code, Government Code - GOV § 19171

The service of a probationary period is required under the following circumstances: (a) when an employee enters or is promoted in the state civil service by permanent appointment from an employment list, (b) upon reinstatement after a break in continuity of service resulting from a permanent separation, or (c) after any other type of appointment situation not specifically excepted from the probationary period requirement by statute or by board rule.