DES MOINES — A Minnesota federal judge must hold hearings to determine whether a proposed settlement for about 100 million Target customers who were victims of a 2013 security breach treats all customers fairly, a federal appeals court says.

The 8th U.S. Circuit Court of Appeals said in an opinion filed Wednesday that Judge Paul Magnuson must review the class certification he approved in November 2015.

Under the settlement, Minneapolis-based Target must establish a $10 million fund. Consumers can claim up to $10,000 if they can document unreimbursed losses. After those claims are paid out, the remaining settlement funds will be divided among consumers who state under oath that they suffered a qualifying loss, but don’t have documentation. Those who suffered no monetary loss from the security breach but could face future identity theft issues receive nothing.