Understanding Medicare enrollment periods can be key to getting the coverage you need without unnecessary expenses or disruptions. While the process can feel overwhelming at times, planning makes all the difference. Let’s walk through essential deadlines and tips to help ensure a smooth Medicare enrollment.

What is Medicare and Why Is It Important?

Medicare is a federal health insurance program designed primarily for individuals age 65 and older. It also provides coverage for certain younger individuals with disabilities or specific health conditions. Medicare plays a vital role in the lives of millions of Americans, giving them access to health care services they might not otherwise afford. As of 2025, approximately 66.4 million Americans are covered by Medicare Parts A and/or B, representing about 19.7% of the U.S. population.1
Medicare covers important health care needs, including:
  • Original Medicare (Medicare Part A and Medicare Part B)
    • Hospital stays (Medicare Part A)
    • Doctor visits and medical services (Medicare Part B)
  • Medicare Advantage plans (Medicare Part C): These are alternative plans offered by private insurers that bundle Part A and Part B benefits, often with additional coverage
  • Prescription drugs (Medicare Part D)
Additionally, private Medicare supplement plans (Medigap) are available to help fill the gaps in coverage that Original Medicare (Parts A & B) might not fully address, such as deductibles, copayments, and coinsurance.

Medicare Enrollment Periods—Don’t Miss These Deadlines

One challenging part of Medicare is understanding when and how to enroll. Missing an enrollment period may lead to delayed coverage, costly penalties, or limited options for the health care you need.

Medicare offers five distinct initial enrollment periods, each tailored to specific circumstances to help beneficiaries choose the coverage that best fits their needs:

Initial Enrollment Period (IEP)

  • Seven-month period to sign up for Medicare Parts A and B
  • Begins three months before you turn 65
    • Example: If you turn 65 on July 8th, your IEP runs from April 1 through October 31
  • If you were born on the first day of the month, it starts a month earlier

Initial Coverage Election Period (ICEP)

  • Seven-month period to sign up for Medicare Advantage (Part C)
  • Begins the same time as your IEP
    • Note: If you delay enrolling in Part B, your ICEP will be three months before the effective date of your coverage for Part B

Medicare Supplement Open Enrollment Period (Medigap OEP)

  • Six-month period to enroll in Medigap
  • Begins the first month you have Medicare Part B and you’re 65 or older
    • Note: If you delay enrolling in Medicare Part B, your OEP will also be delayed
      • Example one: You turn 65 in September and enroll in Medicare Part B on September 1—Medigap enrollment runs September 1- February 28
      • Example two: You turn 65 in September but delay enrolling in Medicare Part B until you turn 67— Medigap enrollment begins when your Part B coverage begins

Special Enrollment Period (SEP)

  • Allows you to enroll in Medicare coverage outside of the standard enrollment windows due to specific life circumstances or qualifying events after you turn 65 (examples: losing employer coverage, moving, institutionalization, other life changes)
  • Most SEPs for Medicare Advantage (C) and Part D drug plans last two months following the qualifying event or notice of the event
  • The SEP for Part B enrollment after employer coverage loss lasts eight months
  • SEP timing may vary depending on event specifics and notification timing

Missing Enrollment Deadlines and Consequences

Missing Medicare enrollment deadlines can have serious financial and health care coverage implications. If you have coverage through your employer, you may decide not to enroll during the IEP. Here are the examples of some of the consequences of missing these critical windows:
  • Missing IEP deadlines for Medicare Part B adds an extra 10% to the premium for every 12-month period you didn’t enroll
  • Missing the IEP deadline may mean you have to wait until one of the other enrollment periods and risk not having coverage
  • Missing the Medigap OEP could cause you to lose the right to purchase the plan
  • Insurers could deny coverage or charge higher premiums

Tips for Navigating Medicare Enrollment

To help you navigate Medicare enrollment and choose the coverage that best fits your needs you should mark important enrollment dates on your calendar and evaluate your current health needs.

Set reminders for the start and end dates for your IEP, ICEP, and Medigap OEP. Give yourself plenty of time to review your options and assess your health care needs.

Consider factors like:
  • How often you visit doctors or specialists
  • Prescription medications you take regularly
  • Whether you need coverage for dental, vision, or hearing
Based on your needs, decide whether Original Medicare, Medicare Advantage, or Medigap supplemental insurance is the best fit for your lifestyle and budget.

Take Advantage of Resources and Support

Navigating Medicare enrollment may be easier with the right partner by your side. At American Fidelity Retirement Services, we offer resources and personalized support to help you make informed decisions. Our team specializes in guiding retirees through the enrollment process, answering questions, and helping to ensure you meet all deadlines. With expert assistance, you can more confidently select the coverage that works best for you.
This blog is up to date as of July 2025 and has not been updated for changes in the law, administration or current events.
This information is general in nature and should not be considered financial, legal or tax advice. Consult an attorney or a tax professional regarding your specific situation.

Sources

  1. Consumer Affairs. “Medicare Statistics: Enrollment, Spending, and Demographics”, 15 May 2024. Accessed on 23 Jun 2025. https://www.consumeraffairs.com/insurance/medicare-statistics.html#medicare-statistics