Definitions for "Donut hole"
the gap in coverage when the enrollee has to pay 100% of the discounted price. It is the period after an enrollee's drug spending exceeds the initial coverage limit and before the enrollee's out-of-pocket expenses reach the TrOOP limit. This is referred to as the donut hole or coverage gap.
The portion of the Medicare prescription drug coverage between $2,250 and $5,100 where you pay 100% of your prescription drug charges
This refers to a "hole" or gap in coverage. The "donut hole" in Medicare Part D, for example, refers to the gap participants fall into after spending $2250 on prescription drugs. Participants must then incur an additional $3600 in out-of pocket expenses to be eligible for drug coverage.