Skip to content
MassArbitration
Class Actions

Ascertainability

The implied requirement that class membership be determinable by objective criteria.

Circuits differ sharply on how demanding this is, with some requiring an administratively feasible method of identifying members and others satisfied by an objective class definition. The split matters most in low-value consumer cases where purchasers left no records.

See also

Published for legal professionals. Analysis and summaries only — not legal advice, and no attorney-client relationship is created by use of this site.

The Mass Arbitration Briefing

The doctrine moves quarterly. Keep up in five minutes a week.

  • Provider rule changes and fee-schedule moves, as they land
  • Every unconscionability ruling that changes how you draft
  • No promotions, no filler — one email, one click to unsubscribe

We use your details only to send the briefing and to verify you work in the field. No sharing, no selling. Unsubscribe any time. See our Privacy Policy.