Medicare · Cornerstone
How to sign up for Medicare
Last reviewed June 11, 20264 min readBy the Goodsurance editorial team Reviewed by the Goodsurance editorial team
Signing up for Medicare is either automatic or entirely on you, and which one it is depends on a single fact: whether you are already drawing Social Security when you turn 65. People get tripped up because they assume it always happens by itself. For a lot of people it does not, and the silence is mistaken for "everything is handled." Here is how to tell which situation you are in, how to actually apply, what to have ready, and what to do if a deadline has already passed.
1First, figure out which situation you are in
If you are already getting Social Security or Railroad Retirement benefits before 65, you are usually enrolled in Parts A and B automatically. A card shows up in the mail a few months before your birthday, and coverage starts the first of your birthday month.
If you are not yet drawing Social Security, nothing happens automatically. You have to apply, and the responsibility for hitting your enrollment window is yours. This has become more common as people delay claiming Social Security to grow the benefit, a sensible move that has the side effect of removing the automatic Medicare prompt. If you are delaying Social Security, you almost certainly have to sign up for Medicare yourself.
If you are not sure which group you are in, assume it is the second one and act accordingly. The cost of applying when you did not strictly need to is a few minutes; the cost of assuming it was automatic when it was not is a penalty.
- Enrollment is usually automatic
- A card arrives in the mail
- Nothing is automatic; you must apply
- Apply through Social Security, not Medicare
2Should you take just Part A, or both?
There is a decision hiding inside "sign up." Part A is premium-free for most people, so taking it at 65 is usually the easy call, with one exception worth knowing: if you contribute to a Health Savings Account, enrolling in any part of Medicare, including free Part A, ends your ability to contribute to that HSA. People who plan to keep working and saving in an HSA past 65 sometimes delay even Part A for that reason.
Part B is the real decision, because it carries a premium and a penalty for late enrollment. If you have no other coverage, take it at 65. If you have active coverage through a large employer, you may be able to wait, which the missed-window section below addresses.
Enrolling in any part of Medicare, including premium-free Part A, ends your ability to contribute to a Health Savings Account. If you plan to keep working and saving in an HSA past 65, that is a reason some people delay even Part A.
3How to actually apply
There are three ways, and the first is the one most people use:
- Online at ssa.gov: the Social Security Administration handles Medicare enrollment, not Medicare itself, which surprises people. The online application is the fastest route for most and takes well under an hour for a straightforward case.
- By phone: call Social Security and apply with a representative, which helps if your situation has wrinkles like employer coverage or a delayed Social Security claim.
- In person: at a local Social Security office, usually by appointment.
You apply through Social Security because they administer enrollment even though the coverage is Medicare. That single quirk explains a lot of the confusion: people search "sign up for Medicare," land on Medicare.gov, and have to be redirected to Social Security to actually enroll.
4What you will need
Have these ready before you start, because hunting for them mid-application is where people stall. Most applications do not require much beyond this, and many people finish online in a single sitting.
What to have ready before you apply
Your Social Security number
The core identifier on the application
Proof of birth
Birth certificate or equivalent
Proof of citizenship or legal residency
If it is not already on file
Employer-coverage details
When it started, plus the employer form if you are delaying Part B
5What happens after you apply
Enrolling in Parts A and B is the beginning, not the end. Once you are approved, you receive your Medicare card and a coverage start date. Two decisions usually follow, and timing them to your start date avoids gaps.
First, drug coverage: Original Medicare does not include it, so most people add a Part D plan, and the clock on the Part D late penalty is running whether you act or not. Second, the bigger fork: stay with Original Medicare and add a Medigap supplement to handle the open-ended 20 percent, or switch to a Medicare Advantage plan that bundles things together. Your enrollment in A and B is what opens those options, and the cleanest path is to have the rest of your coverage chosen and effective by the day your Medicare starts.
6If you missed your Initial Enrollment Period
This happens, and it is recoverable, though sometimes with a cost. The path depends on why you missed it.
If you had no qualifying coverage, you generally enroll during the General Enrollment Period, January 1 to March 31 each year, with coverage starting the month after you sign up. The permanent Part B late-enrollment penalty may then apply, and there can be a gap of several months before coverage begins.
If you delayed because you had real employer coverage at a company with 20 or more employees, you likely qualify for a Special Enrollment Period instead, which lets you enroll without penalty for a set window after your employment or that coverage ends, whichever comes first. The trap inside the trap: COBRA and retiree coverage do not count as the active employer coverage that creates this SEP. Before you assume a penalty applies, confirm which situation is yours, because the difference between the two doors can be significant and is not always obvious from the outside.
If you missed your window
Common questions about Medicare
Quick answers to common questions
Tap any question to expand. Each question links to a fuller standalone answer.
How do I sign up for Medicare?
You sign up for Medicare through Social Security, online at ssa.gov, by phone, or in person at a Social Security office; Medicare itself does not handle enrollment.
The best time is your Initial Enrollment Period, the seven-month window around your 65th birthday. If you already receive Social Security benefits, you are usually enrolled automatically in Part A and Part B. If you are not yet drawing Social Security, you have to apply yourself. After you have Part A and Part B, you can separately choose added coverage like a Part D drug plan, a Medicare Advantage plan, or a Medigap supplement. To talk through which added coverage fits your situation, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
Is Medicare automatic at 65?
Medicare is not automatic for everyone at 65; it depends on whether you already receive Social Security.
If you are drawing Social Security or Railroad Retirement benefits before 65, you are usually enrolled automatically in Part A (hospital) and Part B (medical), and your card arrives a few months before your birthday. If you have not started those benefits, enrollment is not automatic, and you must apply yourself through Social Security during your Initial Enrollment Period, the seven-month window around your 65th birthday. People who qualify through disability are often enrolled automatically after 24 months of benefits. Even when Part A and B are automatic, drug coverage and other plan choices are not. To review your options, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
Where do I enroll in Medicare?
You enroll in Medicare through the Social Security Administration, not through Medicare directly.
You can apply online at ssa.gov, by phone, or in person at a local Social Security office. Railroad retirees apply through the Railroad Retirement Board instead. This applies to Part A (hospital) and Part B (medical). Added coverage works differently: you enroll in a Part D drug plan, a Medicare Advantage plan, or a Medigap supplement through the insurance company offering it or with help from a licensed agent, not through Social Security. Knowing which door to use saves time and helps avoid gaps. To get help choosing and enrolling in added coverage, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
Do I need to sign up for Medicare if I have other insurance?
It depends on the kind of other insurance you have.
If you have active employer coverage through a job with 20 or more employees, where you or your spouse still work, you can usually delay Medicare without penalty and sign up later through a Special Enrollment Period. If your employer has fewer than 20 employees, Medicare often becomes the primary payer, so you typically need to enroll at 65 to avoid gaps. Retiree coverage, COBRA, and marketplace plans generally do not count as active employer coverage, so delaying Medicare with those can trigger a late penalty. The rules turn on whether the coverage is active and the employer's size. To check your specific situation, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
How long does it take to get Medicare after applying?
Coverage timing depends on when you apply within your enrollment window.
If you sign up during the three months before your 65th birthday, your Part A and Part B coverage generally start the first day of your birthday month. If you apply during or after your birthday month, your start date can be delayed by a month or more. Once Social Security processes your application, your Medicare card typically arrives by mail within a few weeks, though it can take longer during busy periods. Applying early in your Initial Enrollment Period, the seven-month window around your 65th birthday, is the best way to avoid a gap in coverage. To plan your timing, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
When can I enroll in Medicare?
Most people can first enroll in Medicare during their Initial Enrollment Period, a seven-month window around your 65th birthday that starts three months before the month you turn 65, includes that month, and ends three months after.
If you miss it, the General Enrollment Period runs January 1 to March 31 each year for Part A and Part B. After you have Medicare, the Annual Enrollment Period from October 15 to December 7 (2026) lets you change Part D drug plans and Medicare Advantage plans, with changes effective January 1. The Medicare Advantage Open Enrollment Period from January 1 to March 31 (2026) lets people already in a Medicare Advantage plan switch once. Special Enrollment Periods may also apply after certain life events, like losing job coverage. To review which window fits you, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
What is AEP in Medicare?
AEP stands for the Annual Enrollment Period, the yearly window when anyone with Medicare can make changes to their coverage.
It runs from October 15 to December 7 (2026), and the changes you make take effect January 1 of the following year. During AEP you can join, switch, or drop a Medicare Advantage plan (Part C), join, switch, or drop a Part D prescription drug plan, and move between Original Medicare and Medicare Advantage. This is the main once-a-year opportunity to review your plan against your current doctors, medications, and budget, since plans can change their costs and coverage each year. AEP is different from the Medicare Advantage Open Enrollment Period, which runs January 1 to March 31 (2026) and only lets people already in a Medicare Advantage plan make one switch. If you want to change plans, AEP is usually the time to do it.
What is the Medicare Open Enrollment Period?
The term Medicare Open Enrollment Period is used two ways, so it helps to be specific.
Most often people mean the Annual Enrollment Period (AEP), which runs October 15 to December 7 (2026) and lets anyone with Medicare join, switch, or drop a Medicare Advantage plan (Part C) or a Part D drug plan, with changes effective January 1. Separately, the Medicare Advantage Open Enrollment Period runs January 1 to March 31 (2026) and lets people already enrolled in a Medicare Advantage plan make one change, such as switching to another Medicare Advantage plan or returning to Original Medicare. There is also a Medigap Open Enrollment Period, a six-month window that begins when you are 65 or older and enrolled in Part B, during which you can buy a Medigap (supplement) policy without health-based pricing. Knowing which one you mean determines what you can change.
Can I change my Medicare Advantage plan in January?
Yes.
If you are already in a Medicare Advantage plan (Part C, your Medicare benefits through a private plan), the Medicare Advantage Open Enrollment Period lets you make one change between January 1 and March 31 (2026). During this window you can switch to a different Medicare Advantage plan, or leave Medicare Advantage and return to Original Medicare, and if you return to Original Medicare you can also add a Part D drug plan. This window is only for people who already have a Medicare Advantage plan on January 1; it is not a time to switch from Original Medicare into Medicare Advantage. You get one change during this period, and it takes effect the first of the month after the plan receives your request. This is separate from the Annual Enrollment Period, which runs October 15 to December 7 (2026). If you missed making a change during AEP, the January to March window is a second chance for current Medicare Advantage members.
What is the Part B late penalty?
The Part B late penalty is a permanent surcharge added to your Part B (medical) monthly premium if you delay enrolling without qualifying coverage.
The penalty is 10% of the standard premium for each full 12 months you could have had Part B but did not sign up. Because it is based on full 12-month periods, waiting two full years would add 20%, and so on. The surcharge is permanent, meaning it stays on your premium for as long as you have Part B, not just for a year. You can avoid it by enrolling during your Initial Enrollment Period or by having qualifying coverage, like active employer insurance, that lets you delay. To check whether a penalty applies to you, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
How much is the Part B penalty?
The Part B penalty adds 10% to your Part B (medical) premium for each full 12 months you could have enrolled but did not.
So one full year late adds 10%, two full years adds 20%, and it keeps climbing with each additional full year of delay. The penalty is calculated as a percentage of the standard premium, which is $202.90 per month in 2026, and the surcharge is permanent: it stays on your premium for as long as you have Part B. Because the base premium can change from year to year, the dollar amount of your penalty can shift too, but the percentage tied to your delay stays the same. To work out what a penalty would mean for you, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
Can I avoid the Part B penalty?
Yes, you can avoid the Part B (medical) penalty by enrolling on time or by having qualifying coverage that lets you delay.
The simplest way is to sign up during your Initial Enrollment Period, the seven-month window around your 65th birthday. If you keep working past 65 and have active employer coverage through a job with 20 or more employees, you can delay Part B without penalty and enroll later using a Special Enrollment Period, which gives you 8 months after that employment or coverage ends, whichever comes first. Watch out: retiree coverage, COBRA, and marketplace plans do not count as qualifying coverage for this purpose, so delaying with those can trigger the penalty. To confirm your coverage qualifies, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
References
- SSA, Social Security AdministrationThe Medicare application, online and in person, and automatic enrollment. ssa.gov
- Medicare.govEnrollment periods and what to do after a missed window.
- CMS, Centers for Medicare & Medicaid ServicesFederal enrollment rules and Special Enrollment Period criteria. cms.gov
- IRS, Internal Revenue ServiceHealth Savings Account rules as they interact with Medicare enrollment. irs.gov