what is the cost of medicare part d

No, you only have EITHER Part A of Medicare OR Part B of Medicare to get Part D. It is not necessary to have both parts to get D. This is completely incorrect according to the Social Security Adm. (This is where you have to sign up for Medicare). I was told this information 9-24-10.

Anyone who has Medicare Part B.

You can get prescription drug coverage (or Medicare Part D) through Medicare ... If, at any point, you drop Medicare Part D and have a break in coverage, restrictions will apply.

Medicare part D is a prescription drug coverage insurance that is a part of your medicare insurance if you qualify. It can be applied for at the medicare.gov website.