Evidentiary Privileges in California And Federal Courts: A Brief Comparison

Tyler Atkinson


Attorneys who appear in both state and federal courts must be familiar with the differences between the two systems.  While some rules have harmonized over time,[1] other procedures are entirely distinct.  As a matter of competence, lawyers who practice in state and federal courts should stay familiar with these differences.  As a matter of strategy, when a party has the option to litigate in either forum, the differences may present a tactical edge.

This article, comparing evidentiary privileges in federal and state actions, is one of a five-part series of articles highlighting particular differences in California versus federal civil procedure.  Other articles in this series examine differences in punitive damages, the jury system, citation to unpublished authorities, and class actions.


The term “privilege” has multiple meanings under the law.  The term may refer to a right or entitlement.[2]  Or, it may refer to a protection for conduct or statements; for example, communications made during litigation or the legislative process are generally privileged from liability.[3]  This article focuses on evidentiary privileges—privileges to exclude matters from discovery or as evidence at trial. 

The body of evidentiary privileges in California and federal courts are fundamentally distinct in one respect in particular: whereas federal evidentiary privileges are almost entirely based on case law,[4] California recognizes only statute-based privileges.  California has no common law evidentiary privileges.[5]  California courts have no power to “create” an evidentiary privilege.[6]  Federal courts, by contrast, have “the flexibility to develop rules of privilege on a case-by-case basis.”[7]

The primary reason for this difference is that, during the drafting of the Federal Rules of Evidence (“FRE”), Congress could not settle on which evidentiary privileges should be recognized.[8]  Congress thus took a path of least resistance.  FRE, Rule 501 simply states:

The common law — as interpreted by United States courts in the light of reason and experience — governs a claim of privilege unless any of the following provides otherwise:

  • the United States Constitution;
  • a federal statute; or
  • rules prescribed by the Supreme Court.

But in a civil case, state law governs privilege regarding a claim or defense for which state law supplies the rule of decision.

The last sentence of this rule is intended to prevent forum shopping.   State law determines privilege issues with respect to state claims.[9] 

Thus, in “federal question” cases governed by federal law, evidentiary privileges are generally a question of the common law.[10]  In state court, and in federal “diversity cases,” California’s statutory law on privileges applies.[11]

Because California’s privileges are statute-based, nearly all of the potential evidentiary privileges may be found in a single chapter of the Evidence Code:

  • “Privilege of Defendant in Criminal Case” (Evid. Code, § 930)
  • “Privilege Against Self-Incrimination” (Evid. Code, § 940)
  • “Lawyer-Client Privilege” (Evid. Code, §§ 950-962)
  • “Lawyer Referral Service-Client Privilege” (Evid. Code, §§ 965-968)
  • “Privilege Not to Testify Against Spouse” (Evid. Code, §§ 970-973)
  • “Privilege for Confidential Marital Communications” (Evid. Code, §§ 980-987)
  • “Physician-Patient Privilege” (Evid. Code, §§ 990-1007)
  • “Psychotherapist-Patient Privilege” (Evid. Code, §§ 1010-1027)
  • “Clergy Penitent Privileges” (Evid. Code, §§ 1030-1034)
  • “Sexual Assault Counselor-Victim Privilege” (Evid. Code, §§ 1035-1036.2)
  • “Domestic Violence Counselor-Victim Privilege” (Evid. Code, §§ 1037-1037.8)
  • “Human Trafficking Caseworker-Victim Privilege” (Evid. Code, §§ 1038-1038.2)
  • “Official Information and Identity of Informer” (Evid. Code, §§ 1040-1047)
  • “Political Vote” (Evid. Code, § 1050)
  • “Trade Secret” (Evid. Code, §§ 1060-1063)

In addition, California recognizes a mediation privilege (Evid. Code, § 1115-1128), and a settlement communication privilege (Evid. Code, § 1152).  California also allows reporters to refuse to disclose “information obtained or prepared in gathering, receiving or processing of information for communication to the public.”  (Evid. Code, § 1070.)

These California privileges have accumulated through the legislative process,[12] just as federal cases have developed federal common law privileges.  While this article is too brief to address all of the nuances between California’s statutes and federal common law, a few selected differences are highlighted below.

Attorney-Client Communications

In California, communications between a lawyer and client are presumptively made in confidence.[13]  This presumption does not appear in federal cases, which hold that, “Because it impedes full and free discovery of the truth, the attorney-client privilege is strictly construed.”[14]  In federal court, a party has the burden to establish the privileged nature of the communication.[15]  “The fact that a person is a lawyer does not make all communications with that person privileged.”[16]


Protections for attorney work product also differ.  California identifies any work performed by an attorney, regardless of whether litigation was contemplated, as protected work product.  An attorney’s work product is absolutely privileged: “A writing that reflects an attorney’s impressions, conclusions, opinions, or legal research or theories is not discoverable under any circumstances.”  (Code Civ. Proc. § 2018.030(a).)

Under the federal system, protected work product is limited to matters created in anticipation of litigation.  Further, Rule 26(b)(3)(A) of the Federal Rules of Civil Procedure allows discovery of such materials if they are relevant and the requesting party has a “substantial need” to obtain them.

Spousal Privilege

In California, a married person has a privilege not to testify against his or her spouse in any proceeding.  (Evid. Code, § 970.)  The federal common law analogy, sometimes referred to as “the adverse spousal testimonial privilege” is limited to criminal proceedings.  See Hawkins v. United States, 358 U.S. 74, 77-78 (1958) (“Adverse testimony given in criminal proceedings would, we think, be likely to destroy almost any marriage.”)


Whether a privilege is available may depend on whether the litigation arises out of state or federal law.  For parties asserting federal claims, the federal common law supplies the potential privileges.  For parties asserting claims under California law, statutes are the only source of privileges.  In a situation where the choice between federal and state privilege law may significantly affect the litigation, a plaintiff should consider whether the action can be litigated using only state or federal causes of action.



For purposes of citation to California authorities, this article follows the California Style Manual (4th ed. 2000).  Federal authorities are cited using the Bluebook (20th ed. 2015).  Code citations are to California state codes, e.g., the California Evidence Code, unless otherwise specified.

[1] For example, California’s electronic discovery rules have generally caught up with their federal counterparts.  California’s Electronic Discovery Act, enacted in 2009, was largely modeled on the federal rules.  See Assem. Com. on Judiciary, Analysis of Assem. Bill No. 5 (2009-2010 Reg. Sess.) (“[m]any of the bill’s specific provisions are drawn from recently enacted federal rules . . . .”).

[2] United States citizens, for example, are entitled to the “privileges and immunities” of residents of each of the individual states.  U.S. Const. art. IV., cl. 1; see Toomer v. Witsell, 334 U.S. 385, 403 (applying the privileges and immunities clause to commercial shrimping).

[3] Civ. Code, § 47; see Hagberg v. California Fed. Bank (2004) 32 Cal.4th 39.

[4] Fed. R. Civ. P. 501.

[5] Welfare Rights Organization v. Crisan (1983) 33 Cal.3d 766, 768-769.

[6] Cal. Law Revision Com. com., West’s Ann.Cal.Evid.Code, foll. § 911; HLC Properties, Ltd. v. Superior Court (2005) 35 Cal.4th 54, 59-60; Roberts v. City of Palmdale (1993) 5 Cal.4th 363, 373.

[7] Trammel v. United States, 445 U.S. 40, 47 (1980); see Dickerson v. Superior Court (1982) 135 Cal.App.3d 93, 99.

[8] The absence of explicit privileges in the federal rules is a byproduct of Congress’s inability to settle on a set of explicit privileges.  See Rules of Evidence, S. Rep. No. 93-1277 (1974).

[9] FRE 501; see Star Editorial, Inc. v. U.S. Dist. Court for Central Dist. of Cal., 7 F.3d 856, 859 (9th Cir. 1993).  This provision of Rule 501 is arguably redundant due to the “Erie doctrine.”

[10] FRE 501; Jaffee v. Redmond, 518 U.S. 1, 8 (1996); Admiral Ins. Co. v. U.S. Dist.Court for Dist. of Ariz., 881 F.2d 1486, 1492 (9th Cir. 1989)  (applying federal common law attorney-client privilege in case involving federal claim).  The only privilege protections explicitly provided under the FRE are found in FRE 502, for attorney-client privilege and work product.

[11] In a breach of contract case concerning an alleged breach of an agreement settling state and federal claims, the Ninth Circuit has imposed federal privilege law.  In re TFT-LCD (Flat Panel) Antitrust Litig., 835 F.3d 1155, 1158–59 (9th Cir. 2016).

[12] For example, California’s human trafficking caseworker-victim privilege was enacted in 2005.  See Stats. 2005, ch. 240, § 4.

[13] Costco Wholesale Corp. v. Superior Court (2009) 47 Cal.4th 725, 733.

[14] United States v. Martin, 278 F.3d 988, 999 (9th Cir. 2002), as amended on denial of reh'g (Mar. 13, 2002). 

[15] Ralls v. United States, 52 F.3d 223, 225 (9th Cir. 1995). 

[16] United States v. Martin, 278 F.3d 988, 999 (9th Cir. 2002) (citing United States v. Chen, 99 F.3d 1495, 1501 (9th Cir. 1996)), as amended on denial of reh'g (Mar. 13, 2002).

About the author Tyler Atkinson

Tyler represents plaintiffs and defendants in civil cases, public entity litigation, and high-stakes disputes.  His clients range from individuals and closely held businesses to Fortune 500 companies.