If you have a group plan, attrition refers to the income left in the plan due to a reduction in the number of beneficiaries who qualify for Educational Assistance Payments (EAPs) in their beneficiary group. Whether they cancelled their Plan or failed to apply for their EAPs, it means that there is a lower number of people that will be sharing the amount of money available for EAPs - which means you get an increased return and/or payment.