Dearborn National will index the amount of pre-disability earnings by the lesser of 10% or the CPI-W. Indexing is used as part of the earnings test to determine if you are still disabled. For example, you are earning $10,000 per month. You become partially disabled and are only able to work 75% of your hours. Your disability earnings are $7,500 so you do meets the definition of disabled (earning less than 80% of your pre-disability earnings). Since you will continue to receive salary increases from your employer, you will eventually exceed the 80% rule even though you are still only working at 75% capacity. With indexing, we increase the original $10,000 each year by the lesser of 10% or the CPI-W to determine if you are still earning less than 80% of your pre-disability earnings.