What Is a Monell Claim? How a City or County Can Be Sued Under Section 1983

Short answer: a federal civil rights lawsuit under 42 U.S.C. section 1983 can name the individual officer, and it can name the city or county that employs the officer. The rules for the second kind of claim come from a 1978 Supreme Court decision, Monell v. Department of Social Services of the City of New York, which is why lawyers call it a "Monell claim." This guide sets out, in their own words, the statute, what the Supreme Court has said, and the model jury instructions the Ninth Circuit publishes for these claims. It also quotes the California statute that governs a public entity's liability for its employees under state law.

The statute

42 U.S.C. section 1983 provides:

"Every person who, under color of any statute, ordinance, regulation, custom, or usage, of any State or Territory or the District of Columbia, subjects, or causes to be subjected, any citizen of the United States or other person within the jurisdiction thereof to the deprivation of any rights, privileges, or immunities secured by the Constitution and laws, shall be liable to the party injured in an action at law, suit in equity, or other proper proceeding for redress ..."

The section derives from section 1979 of the Revised Statutes and was amended in 1979 and 1996.

Monell v. Department of Social Services (1978)

The Supreme Court decided Monell, 436 U.S. 658, on June 6, 1978. On whether a local government can be sued under the statute, the Court wrote that "Congress did intend municipalities and other local government units to be included among those persons to whom § 1983 applies," and that "Local governing bodies, therefore, can be sued directly under § 1983" where the action "implements or executes a policy statement, ordinance, regulation, or decision officially adopted," and that they "may be sued for constitutional deprivations visited pursuant to governmental 'custom.'"

On the limits of that liability, the Court wrote:

"a municipality cannot be held liable under § 1983 on a respondeat superior theory."

"a local government may not be sued under § 1983 for an injury inflicted solely by its employees or agents."

The Court described the case before it as one that "unquestionably involves official policy as the moving force of the constitutional violation found by the District Court."

Three later Supreme Court decisions

Pembaur v. City of Cincinnati, 475 U.S. 469 (March 25, 1986). The Court wrote that "it is plain that municipal liability may be imposed for a single decision by municipal policymakers under appropriate circumstances."

City of Canton v. Harris, 489 U.S. 378 (February 28, 1989). The Court wrote that "the inadequacy of police training may serve as the basis for § 1983 liability only where" the failure to train "amounts to deliberate indifference to the rights of persons with whom the police come into contact," and that "Only where a failure to train reflects a 'deliberate' or 'conscious' choice by a municipality" can a city be liable for such a failure.

Connick v. Thompson, 563 U.S. 51 (March 29, 2011). The Court wrote: "A pattern of similar constitutional violations by untrained employees is 'ordinarily necessary' to demonstrate deliberate indifference for purposes of failure to train." It added that "In Canton, the Court left open the possibility that, 'in a narrow range of circumstances,'" the "unconstitutional consequences of failing to train could be so patently obvious that a city could be liable under §1983 without proof of a pre-existing pattern of violations."

The Ninth Circuit's model jury instructions

The Ninth Circuit, whose district courts include the federal courts in Los Angeles, publishes a Manual of Model Civil Jury Instructions approved by its Jury Instructions Committee. The online instructions are stated to be current as of August 2026. Chapter 9 covers section 1983, and four instructions address claims against "local governing body defendants." Each sets out the elements a plaintiff "must prove ... by a preponderance of the evidence."

Instruction 9.5: official policy, practice, or custom

The third and fourth elements of this instruction read:

"Third, [name of defendant's official or employee] acted pursuant to an expressly adopted official policy or a widespread or longstanding practice or custom of the defendant [name of local governing body]; and

Fourth, the defendant [name of local governing body]'s official policy or widespread or longstanding practice or custom caused the deprivation of the plaintiff [name]'s rights by the [name of defendant's official or employee]; that is, the [name of local governing body]'s official policy or widespread or longstanding practice or custom is so closely related to the deprivation of the plaintiff [name]'s rights as to be the moving force that caused the ultimate injury."

The instruction defines its terms:

"'Official policy' means a formal policy, such as a rule or regulation adopted by the defendant [name of local governing body], resulting from a deliberate choice to follow a course of action made from among various alternatives by the official or officials responsible for establishing final policy with respect to the subject matter in question."

"'Practice or custom' means any longstanding, widespread, or well-settled practice or custom that constitutes a standard operating procedure of the defendant [name of local governing body]. [A practice or custom can be established by repeated constitutional violations that were not properly investigated and for which the violator[s] [was] [were] not disciplined, reprimanded or punished.]"

Instruction 9.6: act of a final policymaker

This instruction, revised June 2025, requires proof that the person "had final policymaking authority from defendant [name of local governing body] concerning these act[s]," that when the person "engaged in these act[s], [name of final policymaker] was acting as a final policymaker for defendant [name of local governing body]," and that the acts "caused the deprivation of plaintiff [name]'s rights; that is, the [name of final policymaker]'s act[s] [was] [were] so closely related to the deprivation of plaintiff [name]'s rights as to be the moving force that caused the ultimate injury."

Instruction 9.7: ratification

The fifth element of this instruction reads:

"Fifth, [name of final policymaker] ratified [name of defendant's employee]'s [act[s]] [failure to act], that is, [name of alleged final policymaker] knew of and specifically made a deliberate choice to approve [name of defendant's employee]'s [act[s]] [failure to act] and the basis for it."

Instruction 9.8: a policy that fails to prevent violations, or a failure to train

The third, fourth, and fifth elements of this instruction read:

"Third, the [training] policies of the defendant [name of local governing body] were not adequate to [prevent violations of law by its employees] [train its [police officers] [employees] to handle the usual and recurring situations with which they must deal];

Fourth, the defendant [name of local governing body] was deliberately indifferent to the [substantial risk that its policies were inadequate to prevent violations of law by its employees] [known or obvious consequences of its failure to train its [police officers] [employees] adequately]; and

Fifth, the failure of the defendant [name of local governing body] [to prevent violations of law by its employees] [to provide adequate training] caused the deprivation of plaintiff [name]'s rights by the [name of defendant's [police officer[s]] [employee[s]]]; that is, defendant [name of local governing body]'s failure [to prevent violations of law by its employees] [to train] played a substantial part in bringing about or actually causing the injury or damage to plaintiff [name]."

The instruction defines deliberate indifference: "'Deliberate indifference' is the conscious choice to disregard a known or obvious consequences of one's acts or omissions. Plaintiff [name] may prove deliberate indifference in this case by showing that the facts available to defendant [name of local governing body] put it on actual or constructive notice that its [failure to implement adequate policies] [failure to train adequately] was substantially certain to result in the violation of the constitutional rights of persons such as plaintiff [name] due to [police officer[s]] [employee[s]]'s conduct."

The California statute for state-law claims

For claims under California law rather than section 1983, Government Code section 815.2(a) provides:

"A public entity is liable for injury proximately caused by an act or omission of an employee of the public entity within the scope of his employment if the act or omission would, apart from this section, have given rise to a cause of action against that employee or his personal representative."

Section 815.2 was added in 1963. The state-law claims that can be brought alongside a section 1983 claim are described in What Do the Bane Act, the Ralph Act, and Section 1983 Each Add to a Police Misconduct Case?, and the claim that must be presented before suing a California public entity under state law is described in How to File a Government Claim Against the City or County of Los Angeles.

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