Individuals eligible for premium-free Part A can enroll in Part A at any time after they are first eligible for the coverage.
Individuals who want premium Part A, Part B or both may only enroll during certain enrollment periods that are outlined in the law. The following enrollment periods apply to both premium Part A and Part B:
Initial enrollment period
General enrollment period, and
Special enrollment period for the working aged, and the working disabled.
Initial Enrollment Period (IEP)
The IEP is a 7-month period that begins 3 months before the month a person turns 65 and ends 3 months after the person turns 65. For someone under age 65 who becomes entitled to Medicare based on disability, entitlement begins with the 25th month of disability benefit entitlement. For these individuals, the IEP begins 3 months before the 25th month of disability benefit entitlement, includes the 25th month, and ends three months after. The IEP for people with ESRD and ALS varies based on their situation.
Coverage begins based on when you enroll during the IEP. If a person enrolls in the first 3 months of the IEP, coverage begins the first month the person is eligible for Medicare. If a person enrolls in any other month of the IEP, coverage will be delayed. Disabled individuals are automatically enrolled in Medicare Part A and Part B after they have received disability benefits from Social Security for 24 months.
General Enrollment Period (GEP)
The GEP takes place from January 1 through March 31 of each year. Part B and Premium Part A coverage begins July 1 of that same year.
Annual Enrollment Period
Medicare open enrollment—also known as Medicare’s annual election period—runs from October 15 through December 7 each year. During this annual window, Medicare plan enrollees can reevaluate their coverage—whether it’s Original Medicare with supplemental drug coverage, or Medicare Advantage—and make changes or purchase new policies if they want to do so.
• Switch from Medicare Advantage to Original Medicare or vice versa.
• Switch from one Medicare Advantage plan to another.
• Switch from one Part-D prescription plan to another.