Cal. Bus. & Prof. Code § 4996.16

Nothing in this chapter shall apply to any clinical social worker from outside this state, when in actual consultation with a licensed practitioner of this state, or when an invited guest of a professional association, or of an educational institution for the sole purpose of engaging in professional education through lectures, clinics, or demonstrations, if he or she is at the time of the consultation, lecture, or demonstration licensed to practice clinical social work in the state or country in which he or she resides. These clinical social workers shall not open an office or appoint a place to meet clients or receive calls from clients within the limits of this state.