California Code, Code of Civil Procedure - CCP § 2032.220

(a) In any case in which a plaintiff is seeking recovery for personal injuries, any defendant may demand one physical examination of the plaintiff, if both of the following conditions are satisfied:

(b) A defendant may make a demand under this article without leave of court after that defendant has been served or has appeared in the action, whichever occurs first.

(c) A demand under subdivision (a) shall specify the time, place, manner, conditions, scope, and nature of the examination, as well as the identity and the specialty, if any, of the physician who will perform the examination.

(d) A physical examination demanded under subdivision (a) shall be scheduled for a date that is at least 30 days after service of the demand. On motion of the party demanding the examination, the court may shorten this time.

(e) The defendant shall serve a copy of the demand under subdivision (a) on the plaintiff and on all other parties who have appeared in the action.