Initial Enrollment Period
Your Initial Enrollment Period is a seven-month window when you first become eligible for Original Medicare. This one-time enrollment period begins three months before your 65th birthday month and ends three months after your 65th birthday month. If your birthday is the 1st of the month, then your Initial Enrollment Period begins four months before your 65th birthday month and ends two months after your 65th birthday month.
Special Open Enrollment Period
If you do not sign up for Original Medicare during your Initial Open Enrollment Period, you may quality for a Special Enrollment Period afterwards. Special Open Enrollment Periods depend on certain eligible life events. For example, you get eight months to enroll in Original Medicare Part B after your group health plan coverage ends.
General Enrollment Period
January 1 to March 31 – This is a General Enrollment Period for Original Medicare Part B (and Premium Part A) often called the “Medicare Part B Enrollment Period.” If you miss your seven-month Initial Enrollment Period, you might have to pay a monthly late enrollment penalty as long as you choose to keep Part B.
Note: You can sign up for Premium-Free Part A any time after your 65th birthday, as there is no late enrollment penalty for Premium-Free Part A. After your Initial Enrollment Period, Part A coverage generally starts 6 months before you actually sign up, but no earlier than your 65th birthday month.
Medicare Supplement Open Enrollment Period
If you prefer to go with Medicare Supplement instead of Medicare Advantage after signing up for Original Medicare, your Medicare Supplement Open Enrollment Period begins on your Original Medicare Part B effective date and ends six months after. This is the time when you can buy a Medicare Supplement plan at the best available rate without answering questions regarding pre-existing health conditions. You can apply for a Medicare Supplement Plan any time of the year after your Medicare Supplement Open Enrollment Period, but private insurance companies can deny you. If you manage to get a Medicare Supplement plan after your Medicare Supplement Open Enrollment Period, you might pay a high monthly premium. There could also be a six-month waiting period before pre-existing conditions are covered.
Annual Open Enrollment Period
October 15 to December 7 – If you are actively enrolled in Original Medicare Part A and Part B, you can enroll in a Medicare Advantage or Part D plan between October 15th to December 7th every year. The selected plan is effective January 1st of the following year.
Medicare Advantage Open Enrollment Period
January 1 to March 31 – This enrollment period only applies to Medicare beneficiaries enrolled in a Medicare Advantage plan. This is an opportunity to enroll in a different Medicare advantage Plan or switch back to Original Medicare by enrolling in a Part D plan.