On February 29, the Supreme Court denied certiorari review in Mullins v. Direct Digital, LLC, No. 15-1776.  The Mullins decision, which arose out of the Seventh Circuit, created a circuit split with the Eleventh and Third circuits with respect to the implicit “ascertainability” requirement that those two circuits had found precluded class certification.  In Mullins, the Seventh Circuit held that a class plaintiff is not required to demonstrate the “administrative feasibility” of ascertaining a class.  Rather, a plaintiff must only demonstrate that the class definition is “defined clearly and based on objective criteria.” 

The “implicit” element of ascertainability has recently gained traction at the district court level as a major obstacle to class certification in certain cases.  The requirement is generally viewed as mandating that class membership be, in practice, objectively ascertainable and not require the extensive use of “mini-trials” to resolve consumerspecific issues with respect to the elements of a class or a class definition.   

The Seventh Circuit’s split on this issue adds to the growing body of law on this topic, and the Supreme Court’s denial of review signals that it will continue to allow that law to develop in the lower courts before providing further guidance.  In the interim, careful review of the status of the law in the applicable circuit where a case is pending is essential when one is considering making an ascertainability argument.