A. One or more members of a class may sue or be sued as representative parties on behalf of all, only if:
Art. 591.Prerequisites; Maintainable Class Actions
Title II. Actions · Chapter 5. Class and Derivative Actions · Last amended 2013 · Last verified July 30, 2026
In one sentenceArticle 591 sets the five prerequisites a class must meet before a Louisiana court will certify it — numerosity, commonality, typicality, adequate representation, and an objectively ascertainable membership — plus the added showing required under whichever of the four certification categories in Paragraph B applies.
Full Text of Art. 591
(1) The class is so numerous that joinder of all members is impracticable.
(2) There are questions of law or fact common to the class.
(3) The claims or defenses of the representative parties are typical of the claims or defenses of the class.
(4) The representative parties will fairly and adequately protect the interests of the class.
(5) The class is or may be defined objectively in terms of ascertainable criteria, such that the court may determine the constituency of the class for purposes of the conclusiveness of any judgment that may be rendered in the case. This prerequisite shall not be satisfied if it is necessary for the court to inquire into the merits of each potential class member's cause of action to determine whether an individual falls within the defined class.
B. An action may be maintained as a class action only if all of the prerequisites of Paragraph A of this Article are satisfied, and in addition:
(1) The prosecution of separate actions by or against individual members of the class would create a risk of:
(a) Inconsistent or varying adjudications with respect to individual members of the class which would establish incompatible standards of conduct for the party opposing the class, or
(b) Adjudications with respect to individual members of the class which would as a practical matter be dispositive of the interests of the other members not parties to the adjudications or substantially impair or impede their ability to protect their interests; or
(2) The party opposing the class has acted or refused to act on grounds generally applicable to the class, thereby making appropriate final injunctive relief or corresponding declaratory relief with respect to the class as a whole; or
(3) The court finds that the questions of law or fact common to the members of the class predominate over any questions affecting only individual members, and that a class action is superior to other available methods for the fair and efficient adjudication of the controversy. The matters pertinent to these findings include:
(a) The interest of the members of the class in individually controlling the prosecution or defense of separate actions;
(b) The extent and nature of any litigation concerning the controversy already commenced by or against members of the class;
(c) The desirability or undesirability of concentrating the litigation in the particular forum;
(d) The difficulties likely to be encountered in the management of a class action;
(e) The practical ability of individual class members to pursue their claims without class certification;
(f) The extent to which the relief plausibly demanded on behalf of or against the class, including the vindication of such public policies or legal rights as may be implicated, justifies the costs and burdens of class litigation; or
(4) The parties to a settlement request certification under Subparagraph B(3) for purposes of settlement, even though the requirements of Subparagraph B(3) might not otherwise be met.
C. Certification shall not be for the purpose of adjudicating claims or defenses dependent for their resolution on proof individual to a member of the class. However, following certification, the court shall retain jurisdiction over claims or defenses dependent for their resolution on proof individual to a member of the class.
Amendment History
Amended by Acts 2013, No. 254, §1, eff. 8/1/2013. Acts 1997, No. 839, §1, eff. 7/1/1997.
Plain-English Summary
Before a Louisiana court will let a lawsuit go forward as a class action, Article 591 requires the party proposing the class to prove five things: the class is too large for everyone to join individually (numerosity), the members share common legal or factual questions (commonality), the representative's claims or defenses look like everyone else's (typicality), the representative will protect the class's interests as well as anyone could (adequacy), and — a requirement Louisiana writes directly into its codal text rather than leaving to case law — the class can be defined by objective criteria a court can apply without digging into the merits of each person's individual claim. That last prerequisite, ascertainability, means a class description built around subjective states of mind or case-by-case merits inquiries will not hold up, no matter how well the other four prerequisites are met.
Meeting Paragraph A gets a proponent only partway. Paragraph B requires an additional showing under one of four categories. The first two track situations where separate lawsuits would create real problems: inconsistent judgments that leave the defendant facing contradictory legal duties, or individual judgments that would as a practical matter decide the case for absent members who never got their day in court. The third category — the one used for most damages class actions — asks whether common questions predominate over individual ones and whether a class action beats the available alternatives, and it lists six factors a court weighs in answering that question, from members' interest in controlling their own cases to the practical burdens of managing a class trial. The fourth lets parties certify a class for settlement purposes alone, even where the predominance-and-superiority showing might not otherwise hold up outside that settlement context.
Paragraph C draws a line class-action lawyers run into often: certification cannot resolve questions that depend on proof specific to one member, like an individual's own damages or reliance. But the article does not let the court walk away from those questions once it certifies the common ones — it directs the court to keep jurisdiction over the individual issues, so the same proceeding that decided the class-wide questions stays available to sort out what is left.
Frequently Asked Questions
What are the five prerequisites for certifying a class action in Louisiana?
Numerosity (the class is too large to join everyone), commonality (shared legal or factual questions), typicality (the representative's claims look like the class's), adequacy (the representative will protect the class's interests), and an objectively ascertainable class definition that a court can apply without probing the merits of each member's claim.
What is the ascertainability requirement, and why does it matter?
It requires that a class be defined by objective criteria — dates, transactions, product models, and similar facts — rather than by criteria that would force the court to evaluate each potential member's claim on the merits just to figure out who belongs in the class. A class defined around a subjective state of mind, for instance, would fail this prerequisite even if every other requirement were met.
What is a predominance-and-superiority class action?
It is the certification category in Article 591(B)(3), most often used for damages classes, requiring the court to find that common questions outweigh individual ones and that resolving the case as a class action works better than the alternatives, judged against six listed factors.
Does certifying a class mean every member's individual damages get decided together?
No. Paragraph C bars a court from certifying a class to adjudicate issues that depend on proof individual to a specific member, such as each member's own damages. The court instead retains jurisdiction to resolve those individual issues after the common questions are decided.
Can a class be certified for settlement only?
Yes. Article 591(B)(4) lets parties who have reached a settlement seek certification under the predominance-and-superiority category for settlement purposes, even if the class might not otherwise meet that category's requirements for litigation.
Source & verification. Article text is reproduced verbatim from
the vLex (Louisiana Code of Civil Procedure, 2026 Edition). Enacted by the Louisiana Legislature.
Last verified July 30, 2026.
· Official source
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