You can create plan exclusions for supplemental plans to prevent customers from subscribing to more than one supplemental plan in the same plan group at the same time. In Aria, you cannot assign a customer a new supplemental plan that is in the same plan group as the customer’s current supplemental plan without first canceling the customer’s current supplemental plan. However, you can assign a supplemental plan that is in a different plan group from the customer’s current supplemental plan.