Medicare basics
How and when do I enroll in Medicare?
Most people first qualify at 65, but work coverage, disability and other events can change the path. Use the private planner to find your likely starting point, then confirm the dates before you act.
Medicare enrollment window planner
When can I enroll in Medicare?
Choose the situation closest to yours. For a standard age-65 case, the tool estimates the exact seven-month window. For exceptions, it explains the likely path without making an eligibility decision.
Private, browser-only tool
Find your likely Medicare window
Your guidance will appear here
Choose one situation. We will show the most likely starting point, important exceptions and official next steps.
Educational estimate only, not an eligibility determination or a plan recommendation. No answers are stored.
Three (or sometimes four) months before your 65th birth month
Your Initial Enrollment Period generally opens three months before your birth month. If your birthday is on the first, Medicare generally uses the prior month as your eligibility month, so the window opens one month earlier.
Your Initial Enrollment Period
It normally begins three months before your eligibility month, includes that month, and ends three months after. The first-day birthday rule shifts the eligibility month back by one.
When your Medicare card arrives
Once you have your Medicare number and coverage dates, you can request enrollment in an eligible Medicare Advantage or Part D plan. Medigap has separate enrollment rules.
Every year after that
We review your plan during the Annual Enrollment Period and tell you what changed. Plans, networks and drug formularies all move year to year.
How do I get started?
You can trust CSG Insurance Pros agents to explain the process to you. Each plan is unique and it may be difficult to evaluate what fits your specific needs. Just because a plan works for a friend or family member does not mean it will work for you. A licensed agent can explain the tradeoffs among options CSG represents that are available in your ZIP code.
When can I enroll for Medicare?
Most people who meet Medicare’s citizenship or residency requirements first become eligible at 65. However, if you have been receiving Social Security or Railroad Retirement Board benefits at least four months before then, you will generally be enrolled automatically in Parts A and B. Otherwise, you usually sign up through Social Security or the Railroad Retirement Board, as applicable. After that, you can choose how to receive coverage and can enroll in an eligible plan directly; help from an insurance agent is optional.
Those who have not already begun to draw Social Security benefits will generally need to sign up through Social Security or the Railroad Retirement Board, as applicable. Your Initial Enrollment Period generally begins three months before the month you turn 65, includes your birth month, and ends three months after. If your birthday is on the first day of a month, Medicare generally treats the prior month as your eligibility month, so the window begins and ends one month earlier. Once you have the Medicare number and coverage dates you need, you can request enrollment in an eligible Medicare Advantage or Part D plan. Medigap has separate eligibility and enrollment rules. Medicare’s official sign-up guide can help you confirm the path for your situation.
You may be able to delay Part B without a penalty if you qualify for a Special Enrollment Period based on group health coverage from your own or your spouse’s current employment. Retiree coverage and COBRA do not work the same way. Confirm the exact coverage and timing with the employer benefits administrator and Social Security or Medicare before delaying enrollment.
Are there penalties for enrolling late?
If you do not enroll in Part B when first eligible and do not qualify for a Special Enrollment Period, you may owe a monthly late-enrollment penalty for as long as you have Part B. There is a separate Part D penalty tied to gaps in creditable drug coverage, described on our types of Medicare plans page.
Enrollment questions
- When can I enroll in Medicare?
- Most people first become eligible for Medicare at 65. People receiving Social Security or Railroad Retirement Board benefits at least four months before turning 65 are generally enrolled in Parts A and B automatically; others usually sign up through Social Security or the Railroad Retirement Board, as applicable. You can then choose how to receive coverage and may enroll in an eligible Medicare Advantage or Part D plan directly or with optional help from an agent.
- What if I have not started Social Security yet?
- If you are not enrolled automatically, sign up for Medicare through Social Security or the Railroad Retirement Board, as applicable, during your Initial Enrollment Period. It generally begins three months before the month you turn 65. If your birthday is on the first day of a month, Medicare generally uses the prior month as your eligibility month, so the window starts one month earlier. After you have the Medicare number and coverage dates you need, you can request enrollment in an eligible Medicare Advantage or Part D plan; Medigap has separate eligibility and enrollment rules.
- Can I delay Medicare enrollment without a penalty?
- You may be able to delay Part B without a penalty if you qualify for a Special Enrollment Period based on group health coverage from your own or your spouse's current employment. Retiree coverage and COBRA do not work the same way. Confirm your exact situation with the employer benefits administrator and Social Security or Medicare before delaying enrollment.
- Are there penalties for enrolling late?
- Yes. If you do not enroll in Part B when first eligible and do not qualify for a Special Enrollment Period, you may owe a monthly late-enrollment penalty for as long as you have Part B. Part D has a separate penalty tied to gaps in creditable drug coverage.
Talk to a licensed Arizona Medicare agent
No separate client fee, no obligation, and no pressure. Tell us how to reach you and we will help you compare plan options from the carriers CSG represents that are available in your ZIP code.
Or explore our Medicare FAQs and latest articles.