Roller coasters make some people sick. Combine 'em with doughnut holes, and it can make for a nasty ride. We're speaking here of Part D, Medicare's new prescription drug plans, most of which have a "doughnut hole" -- a gap in coverage where subscribers pay the full cost of all their prescriptions. The gap begins when initial coverage expires and ends when the beneficiary has spent $3,600 out-of-pocket for drugs in a given year.

Seniors nationwide are assessing the dozens of drug plans that will begin operating on Jan. 1. Many want to choose the one with the lowest monthly premium, says Leta Blank, director of Montgomery County's Senior Health Insurance Assistance Program (SHIP). But that strategy can mean huge out-of-pocket costs some months, and low ones other months.

What's Best for Mom? Take, for example, this reporter's mother, Mae Barrett, 85, who routinely uses 14 prescription drugs, both brand names and generics, for arthritis, asthma, osteoporosis and glaucoma.

Under the plan with the lowest monthly premium available to her -- $6.44 a month -- Barrett would pay $367 for her drugs in January (including a deductible of $250), then $182 per month in February and March. Her bill would jump to $599 in April, and top out at $703 for the months of May, June and July. Her outlays would decline to $202 in August, then drop to $57 per month for September through December. Her total spending for the year under this Humana Standard plan, including premiums and deductible, would be $3,944.40. (These calculations are based on drug prices posted last week by Humana; they're subject to change.)

But Wait A few plans in the Washington area partially cover generic drugs during the doughnut hole period. And one -- Humana's PDP Complete -- offers doughnut hole coverage for brand names as well.

Joining the Complete plan would cost Barrett $52.88 a month in premiums, but it would also mean steady drug costs for her until she reaches the $3,600 limit, at which point the plan picks up 95 percent of drug costs for the remainder of the year. She would pay $335 per month for her 14 drugs from January through October. Her November bill would be $254, and she would pay only $57 for December. Total spending, including premiums: $4,273.07.

The Complete plan, which has a zero deductible, was designed for people with high drug costs and those who want "fewer moving parts," said Humana spokesman Scott Latimer.

Do the Math While the Complete plan would cost almost $330 more than the Standard option by year's end, Barrett said she would be happy to pay the extra dollars to avoid huge bills in the middle of the year.

If your drug costs aren't high, recommends Susan Knight, program director for Anne Arundel County's SHIP, pick the plan that covers most or all of your drugs, lets you use your preferred pharmacy and offers you the lowest total out-of-pocket payments.

-- Lisa Barrett Mann

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