Remember that Open Enrollment for Medicare Part D prescription drug plan ends December 31. After that, no changes can be made until next November when Open Enrollment begins again.
Copays, premiums and drug formularies have changed for many plans, so be sure to double check your sepcific coverage before the deadline. Compare plans at the Medicare web site.
Changes to Part A, B,or C can be made until March 31. These are the medical and hospital coverage plans. After March 31, enrollees must stay put in their selected plan until Open Enrollment begins next November 15.