Until December 31, Medicare Part D is offering an “open-enrollment” period, meaning that seniors can change their prescription drug coverage to pick a new plan that better meets their needs. The sign-up period for next year's coverage began November 15.

Drug coverage, known as Medicare Part D, was launched in 2006 for people 65 and older with no other prescription drug insurance and for younger people receiving Social Security benefits. It offers myriad private health insurance plans from which to choose, each with different cost and drug choices.

Here is a bird’s eye view of Medicare’s so called parts. Part A, as most of you know, covers hospitalizations and most people get Part A automatically at age 65 and at no cost. Part B, the most popular part of Medicare, covers visits to doctors, the services of doctors in the hospital and most labs, X-rays and tests ordered by a doctor. Medicare pays 80 percent of the approved costs. Part C is private insurance.

You can search for prescription plans and ratings online. You should have a handbook, mailed in October that shows how well each plan performs in terms of customer service and drug pricing. You'll need to tally up out of pocket expenses to make a decision about which Medicare part D plan is best for you in 2009. Medicare Advantage beneficiaries can change or cancel their plan between Jan. 1 and March 31, 2009. During that time, no change can be made to your Medicare Medical Savings Account Plan.

You can also visit your local State Health Insurance Assistance Program (SHIP) office if you prefer personalized help. You can also call 1800-Medicare if you have questions. Explore the 2009 Medicare & You handbook that you should have received last month.