Seniors should shop among Medicare prescription drug plans to ensure the coverage they're getting is the cheapest and most comprehensive available, the federal Medicare administrator says.

Kerry Weems visited North Dakota on Monday to meet with hospital officials in Dickinson and listen to comments at a health-care forum in Bismarck. He was accompanied by North Dakota's Democratic congressional delegation, Sens. Kent Conrad and Byron Dorgan and Rep. Earl Pomeroy.

North Dakota seniors who are eligible for the prescription drug program, which is called Medicare Part D, have until Dec. 31 to change an existing plan or sign up for one. Adam Hamm, the North Dakota insurance commissioner, said North Dakota seniors have 52 plans to choose from.

Weems said it was important for seniors to know which drugs they need, which plan offers coverage of them, and whether their regular pharmacy handles it.

"Now's the time to shop and to make sure you're in the right plan," he said. "We have a lot of people who are in the program now, but what is important is to make sure that you are in the right plan."

He recently helped his mother choose a new plan, and found one that is expected to cost less than $800 annually, when she has been paying more than $1,600 for four medications, Weems said.

"And she was able to use the same drugs and go to the same pharmacy," he said. "That's how shopping can really make a difference, and we really make it easy for people to shop."

Weems is administrator for the federal Center for Medicare and Medicaid Services, which is part of the Department of Health and Human Services.

Pomeroy said 94 percent of eligible North Dakota seniors are signed up for Medicare prescription drug coverage.

"This is a unique insurance opportunity, the opportunity to evaluate and then move without penalty if you find a better deal out there," Pomeroy said. "Sometimes, even if you're happy with the plan that you have, it doesn't mean you shouldn't look at what else might be available."