Q: I enrolled in a Medicare Part D drug plan last year. My co-payments have been reasonable until the other day. I went to the drugstore and was told I had to pay full price for my medicines. The pharmacist told me I was in the gap. I never heard of such a thing. What do I do?

A: It is unfortunate that you had to learn about the Part D gap in such a way. Medicare Part D was designed to help cover the out-of-pocket costs of prescription medicines, but Medicare Part D does not eliminate your out-of-pocket costs. Part D is designed to have an initial coverage limit. In 2009 the initial coverage limit is set at $2,700 per year. Until you reach this limit, your Medicare Part D plan helps pay a portion of the cost of medicine.

Keep in mind that when calculating this limit, the plan counts what you have paid for the medicines and what the plan has paid for the medicines. Once your medicine costs surpass $2,700, you enter the gap in coverage and will have to pay full price for your medicines.

You will remain in the gap until the first of two things occurs: Jan. 1 arrives and you start a new initial coverage period; or you enter a catastrophic coverage benefit.

Since the beginning of the year, your drug plan is keeping a running total of what you have paid out of pocket for your medicines. All of the co-payments you paid are added to all of the full-price payments you made during your coverage gap. Once the tally of the total annual out-of-pocket costs you have paid for your medicines (excluding your premium costs) reaches $4,350, you will have catastrophic coverage. At this point the cost you pay for your medicines will greatly decrease.

While all this explains the technicalities of initial coverage, the gap and catastrophic coverage, it does not help with the cost you are facing now that you are in the gap. You will want to look at subsidy programs that could help reduce your out-of-pocket costs.

If your income is below $1,353.75 per month (individual) or $1,821.25 per month (married couple) and your assets are below $12,510 (individual) or $25,010 (married couple), contact Social Security to apply for the Extra Help for Medicare Part D. If approved for this program, your out-of-pocket costs when you enter the gap will be limited.

Some Maryland residents qualify for the state's Senior Prescription Drug Assistance Program (SPDAP), which provides some assistance in the gap. For more information on this program, call SPDAP at 800-551-5995.

In addition, you may want to talk with your physician about lower-cost medicines. Ask for samples, too.

Many people find it helpful to budget their money in the beginning of the year when they have coverage under Part D. When they hit the gap, they have set money aside to pay for their higher medicine costs. Again, it is unfortunate you had to learn about the gap through this experience. Hopefully, one of these suggestions will help reduce your costs while you are in the Medicare Part D gap.