California Code, Business and Professions Code - BPC § 6759

The board, upon application therefor, on its prescribed form, and the payment of the fee fixed by this chapter, may issue a certificate of registration as a professional engineer, without written examination, to any person holding a certificate of registration issued to him or her by any state or country when the applicant's qualifications meet the requirements of this chapter and rules established by the board.  The board shall not require a comity applicant to meet any requirement not required of California applicants.  For purposes of this section, equivalent second division examinations shall be written examinations prepared by or administered by a state or territory either by single or combined branch at the level generally administered by the board to persons who passed or were exempted from the first division examination.  Applicants who have passed an equivalent second division combined branch or a single branch examination in a branch not recognized for registration in California shall be registered in the branch in which their experience and education indicate the closest relationship.