If you or a loved one are eligible for Medicare soon, you're probably feeling overwhelmed at this point with all the "stuff" that's come in the mail. You may have figured out that you'll need a Medicare supplement (also called Medigap) policy to cover the things that original Medicare doesn't cover.

But you may be feeling a little confused about the prescription drug part. The short answer is this: You'll also need to purchase a separate plan for prescription drug coverage (a PDP, for short), also called Medicare Part D.

I know this sounds a little clunky, as in, "Why the heck isn't it just part of the Medicare supplement?" and I really can't tell you why the government opted to do it this way, but they did. The good news is that Medicare didn't offer ANY prescription drug coverage until 2004, so having the coverage at all is a great help to many people.

Since there are a multitude of plans offered by a host of different insurance company, the best way to figure out which plan will work best for you is to use the Plan Finder Tool on the Medicare.gov website. I recommend using the Personalized Search, since this lets you enter your medications. It will take into account the PDP's monthly premium, the tier(s) of your drugs, copays, deductibles, and other parameters that will affect your overall costs.

Because the plans that are offered change constantly, not to mention that people's medication needs are always subject to change, each year a Medicare recipient has an opportunity to change PDPs. The enrollment period for that is from October 15 - December 7th. The effective date for all PDP changes is 1/1/12.

So I recommend using Medicare's Plan Finder Tool when you're first eligible for Medicare Parts A & B, and then again during the PDP special enrollment period toward the end of each year, especially if your plan or your drugs have changed during the year. If you're happy with the plan you have and it's working, you can do nothing and stay on the same plan.