You may sign up for Medicare Part D prescription drug coverage when you first become eligible for Medicare (three months before the month you turn age 65 until three months after you turn age 65). If you get Medicare due to a disability, you can join from three months before to three months after your 25th month of cash disability payments, according to Medicare.gov

If you don't sign up for Medicare Part D when you are first eligible, however, you may pay a penalty for late enrollment. This penalty is added to your Medicare Part D drug plan’s premium and you will have to pay it for as long as you have Part D coverage. To determine what the penalty for late enrollment would be, ask your Health Mart pharmacist for assistance, or call 1-800-MEDICARE.

If you didn't join Part D when you were first eligible for the benefit, your next opportunity to enroll will be from November 15 to December 31, unless you are permitted a Special Enrollment Period (SEP). However, keep in mind that late enrollment could result in higher Part D premiums.