Article 9. Class Actions · Last amended 1975 · Last verified July 21, 2026
Not every class action needs to cover the whole case or treat the class as one uniform group. CPLR 906 gives courts two ways to narrow the scope of class treatment. First, an action can proceed as a class action on particular issues only, leaving other issues to be resolved outside the class-action framework, such as through individual proof of damages after a class-wide liability finding.
Second, the court can divide a class into subclasses when members' interests or circumstances differ enough that one class-wide resolution wouldn't fit everyone. Each subclass is then treated as a class in its own right, which means the rest of Article 9, prerequisites, certification, notice, judgment, and everything else, applies separately to each subclass rather than to the case as a whole.
Yes. CPLR 906 allows an action to be brought or maintained as a class action with respect to particular issues, leaving other issues to be resolved separately.
A subclass is a subset of the certified class whose members share interests or circumstances different enough from the rest of the class that they need their own class treatment under CPLR 906.
Yes. CPLR 906 says the provisions of Article 9 apply to each subclass as though it were its own class, which includes the CPLR 901 prerequisites.
Yes. CPLR 906 directs that the article's provisions be construed and applied to each subclass, or to the issues certified for class treatment, just as they would to a full class action.
When some members have interests that diverge from the rest of the group, for example different damages theories or different legal defenses, treating them as separate subclasses keeps each subgroup's representation and notice suited to its own situation.
Yes, in practice a subclass with distinct interests typically needs its own representative capable of adequately representing that subclass, since CPLR 906 treats each subclass as a class under the rest of Article 9.
Add, L 1975, ch 207, § 1, eff Sept 1, 1975.