Every year from Nov. 15 to Dec. 31, people with Medicare Part D can switch to a different Medicare Part D plan. Your current plan is probably making some changes for 2008. When you receive the notice of changes from your plan in October, call the Federation’s Health Plan Information Center if you’d like help determining how changes in your plan will be affect you in 2008. If you have Medicare Parts A or B, but never enrolled in Part D, you can join a Part D plan during the Annual Enrollment Period. All changes made during this time take effect Jan. 1, 2008.