California Code, Business and Professions Code - BPC § 2946

(a) The board shall grant a license to any person who passes the board's supplemental licensing examination and, at the time of application, has been licensed for at least two years by a psychology licensing authority in another state or territory of the United States or Canadian province if the requirements for obtaining a certificate or license to practice psychology in that state, territory, or province were substantially equivalent to the requirements of this chapter.

(b) A psychologist certified or licensed in another state, territory, or province who has applied to the board for a license in this state may perform activities and services of a psychological nature without a valid California license for a period not to exceed 180 calendar days from the time of submitting their application or from the commencement of residency in this state, whichever first occurs.

(c) A psychologist certified or licensed in another state or province who is married to, or in a domestic partnership or other legal union with, an active duty member of the Armed Forces of the United States and who has made application to the board for a license in this state may perform activities and services of a psychological nature without a valid license for a period not to exceed twelve months from the time of submitting their application or from the commencement of residency in this state, whichever first occurs.

(d) The board at its discretion may waive the examinations when in the judgment of the board the applicant has already demonstrated competence in areas covered by the examinations.  The board at its discretion may waive the examinations for diplomates of the American Board of Professional Psychology.  An applicant shall take and pass the required examinations unless waived by the board pursuant to this section.