California Code, Business and Professions Code - BPC § 6730

In order to safeguard life, health, property and public welfare, any person, either in a public or private capacity, except as in this chapter specifically excepted, who practices, or offers to practice, civil engineering, electrical engineering or mechanical engineering, in any of its branches in this state, including any person employed by the State of California, or any city, county, or city and county, who practices engineering, shall submit evidence that he or she is qualified to practice, and shall be licensed accordingly as a civil engineer, electrical engineer or mechanical engineer by the board.