CA Civ Proc Code Section 2032.020

(a)

Any party may obtain discovery, subject to the restrictions set forth in Chapter 5 (commencing with Section 2019.010), by means of a physical or mental examination of (1) a party to the action, (2) an agent of any party, or (3) a natural person in the custody or under the legal control of a party, in any action in which the mental or physical condition (including the blood group) of that party or other person is in controversy in the action.

(b)

A physical examination conducted under this chapter shall be performed only by a licensed physician or other appropriate licensed health care practitioner.

(c)

A mental examination conducted under this chapter shall be performed only by a licensed physician, or by a licensed clinical psychologist who holds a doctoral degree in psychology and has had at least five years of postgraduate experience in the diagnosis of emotional and mental disorders.