California Code of Civil Procedure 2034.410

On receipt of an expert witness list from a party, any other party may take the deposition of any person on the list. The procedures for taking oral and written depositions set forth in Chapters 9 (commencing with Section 2025.010), 10 (commencing with Section 2026.010), and 11 (commencing with Section 2028.010) apply to a deposition of a listed trial expert witness except as provided in this article.

Source:  CCP 2034.410