Initial Enrollment Period (IEP)

The Initial Enrollment Period (IEP) is the first opportunity most individuals have to enroll in Medicare. This enrollment window is based on a person’s 65th birthday and determines when Medicare coverage can begin without delay or penalty.

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When the Initial Enrollment Period Occurs

For most individuals, the Initial Enrollment Period begins three months before the month of their 65th birthday, includes the birthday month, and continues for three months after. This creates a seven-month enrollment window.

When Coverage Begins

The effective date of Medicare coverage depends on when enrollment occurs during the Initial Enrollment Period. Enrolling before the birthday month generally allows coverage to begin on the first day of the birthday month. Delayed enrollment within the window may result in later coverage start dates.

What Can Be Enrolled In During IEP

During the Initial Enrollment Period, eligible individuals may enroll in Medicare Part A and Part B. They may also choose to enroll in a Medicare Advantage plan (Part C) or a standalone Medicare Part D prescription drug plan once enrolled in Part A and Part B.

Delaying Enrollment

Individuals who delay enrollment in Medicare Part B or Part D when first eligible and who do not have qualifying coverage may be subject to late enrollment penalties. Whether delaying enrollment is appropriate depends on individual circumstances, including active employer coverage.

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Disclaimer: This information is provided for educational purposes only and is based on publicly available guidance from the Centers for Medicare & Medicaid Services (CMS). It has not been reviewed or endorsed by Medicare, CMS, or any federal agency. This content does not constitute plan-specific advice. For individual coverage questions, please consult a licensed insurance professional.