Medicare Part D Coverage Gap ("Donut Hole")
Medicare Part D plans have a Coverage Gap, which is a temporary limit on what your drug plan will pay for prescription drug costs. If you do not receive a subsidy such as Extra Help from Medicare, or aren’t enrolled in a plan that offers additional Gap coverage, the combined amount you and your Part D plan spend on your Medicare Part D costs (not including premiums), determines if and when you will reach the Gap. That combined amount is $3,820 (in 2019).
While in the Gap, you will pay 37% of the cost for generic drugs, and 25% of the cost for brand drugs in 2019. You leave the Gap when you alone (not what the plan spends) spend a total of $5,100 in 2019. You then enter the "Catastrophic Coverage" stage, where the costs of your prescriptions are usually lower.