Short answer: These are programs that stop manufacturer drug coupons from counting toward your deductible or out-of-pocket maximum. With an accumulator, coupon dollars don’t count; with a maximizer, the coupon’s value is spread across the year and also doesn’t count toward your limits.
When you use a drug-manufacturer copay coupon, a copay accumulator program prevents that coupon amount from applying to your deductible or out-of-pocket maximum, so once the coupon runs out, you can face the full cost again. A copay maximizer goes further, spreading the coupon’s maximum value evenly across the plan year, again without it counting toward your limits. These programs lower the plan’s drug spend but can leave patients on expensive specialty drugs with surprise costs, so it’s worth knowing if your plan uses one.