The Medicare Part D drug plan coverage gap is contracting, although it's not scheduled to close fully until 2020. The coverage gap -- known as the doughnut hole -- is the period when recipients pay all drug costs themselves. About 20 percent of Part D recipients hit the doughnut hole in past years. Of those who enter the coverage gap, 90 percent do so between June and December.

This year, Medicare recipients get a 50 percent discount on generic drugs and a 7 percent discount on brand-name drugs during the coverage gap. Still, the government estimates that a quarter of those in the gap stop taking or cut back on medications, so it's important to know if or when you will hit the doughnut hole.

AARP offers a calculator that does the work for you after you input your medications.

Access the calculator at

DON'T MISS THIS LIMITED-TIME OFFER1 5 months for only $1Save on Unlimited Digital Access