Stage 1 · Medicare path
How to enroll in Medicare
This page walks you through the full Medicare enrollment process from start to finish. By the end you will have made your coverage decisions, completed your enrollments, and have a card in your wallet. If you are not sure whether Medicare is the right path for you, start at the Stage 1 overview first.
Already enrolled? Check what you have in place.
Tick each item that is true for you. If anything is missing, that section on this page will tell you how to fill it in.
I am enrolled in Medicare Part A (hospital coverage) and have my Medicare card.
I am enrolled in Medicare Part B (doctor and outpatient coverage) and Part B is active.
I have decided between Original Medicare and Medicare Advantage, and have enrolled in my chosen path.
If I chose Original Medicare, I have enrolled in a Medigap plan or have decided not to.
I am enrolled in a Part D prescription drug plan, or my plan includes drug coverage.
Checking these boxes does not save your answers. This is a reading aid only.
Part one
When you can enroll
Medicare enrollment is not open all the time. There are specific windows, and missing the right one can mean waiting months for coverage to start or paying a permanent penalty for the rest of your life. There are three main enrollment windows.
Most common
Initial Enrollment Period
The seven-month window tied to your 65th birthday. Opens three months before the month you turn 65, includes your birthday month, and runs three months after. This is the main window for most people entering Medicare for the first time.
If you delayed
Special Enrollment Period
An eight-month window available to people who delayed Medicare because they had qualifying employer coverage. Opens when that employer coverage ends or employment ends, whichever comes first. No penalty applies if you enroll within this window.
Last resort
General Enrollment Period
January 1 through March 31 each year. Available if you missed both the Initial and Special Enrollment Periods. Coverage does not start until July 1 and a late enrollment penalty applies permanently to your Part B premium.
Enrolling in the first three months of your Initial Enrollment Period means coverage starts on time.
If you enroll in months four through seven of your Initial Enrollment Period, your coverage start date is delayed by one to three months. If your 65th birthday is approaching and you want Part B active immediately, enroll before your birthday month, not after.
Part two
How to sign up
If you already receive Social Security retirement benefits, you are enrolled automatically and your Medicare card arrives by mail about three months before your 65th birthday. If you are not yet receiving Social Security, you need to actively enroll. Pick the method that works best for you.
Fastest
Online
About 10 minutes. Immediate confirmation.
Go to ssa.gov/medicare/apply and complete the application. You will need your Social Security number, date and place of birth, and citizenship information. You receive a confirmation immediately and your Medicare card follows by mail.
If you have questions
By phone
1-800-772-1213. Speak with a representative.
Call Social Security at 1-800-772-1213. A representative walks you through the application and can answer questions about your specific situation. Expect longer wait times during busy periods. TTY users can call 1-800-325-0778.
In person
Local office
Schedule ahead to reduce wait time.
Find your nearest Social Security office at ssa.gov/locator. Bring your Social Security card, a government-issued photo ID, and proof of age such as a birth certificate or passport. Scheduling an appointment in advance significantly reduces wait time.
Enrolling at Social Security gives you Parts A and B. Choosing a plan comes next.
The Social Security step only covers Original Medicare Parts A and B. The decision about Medicare Advantage vs. Original Medicare, choosing a Medigap plan, and adding Part D all happen separately after. If you choose Medicare Advantage, enroll through medicare.gov/plan-compare or directly with the plan - not through Social Security.
Part three
The decision that matters most
Once you have Parts A and B, you face the most consequential choice in Medicare: stay with Original Medicare or switch to Medicare Advantage. This is not a minor preference. It shapes your costs, your access to doctors, and your flexibility for years to come. Neither option is right for everyone.
Path one
Original Medicare
Parts A and B, plus private Medigap and Part D
Accepted by any doctor or hospital in the country that takes Medicare. No networks, no referrals.
Benefits do not change year to year. What you have this year, you have next year.
With a Medigap plan, out-of-pocket costs are highly predictable and often very low.
Higher monthly cost when you add Medigap and Part D premiums on top of Part B.
No extra benefits like dental, vision, or gym memberships.
Best fit for people who want full provider freedom and predictable costs, and can afford higher monthly premiums.
The long-term value: Lower surprise costs, no network restrictions, and the stability of a benefit structure that does not change. Often the better choice for people with complex health needs or specialists they want to keep.
Path two
Medicare Advantage
Part C, an all-in-one private plan
Lower or zero monthly premium in many plans. Some plans have $0 premium after Part B.
Often includes dental, vision, hearing, and other benefits Original Medicare does not cover.
Drug coverage usually bundled in, so no separate Part D plan needed.
Restricted to a network of providers. Seeing out-of-network doctors usually costs more or is not covered.
Plans can change benefits, premiums, and networks every year at Open Enrollment.
Prior authorization required for many services, including some hospitalizations and specialist visits.
The long-term value: Lower upfront cost can be attractive, especially for healthy people. The trade-off is less flexibility and more administrative burden when you need care. Plans vary widely in quality.
Switching back from Medicare Advantage to Original Medicare is not as simple as switching in.
You can switch plans annually during Open Enrollment, but switching from Medicare Advantage back to Original Medicare does not automatically restore your Medigap coverage. In most states, insurers can review your health history and deny your Medigap application after the initial open enrollment window has passed. If you think you may want Medigap in the future, enrolling in Original Medicare plus Medigap at the start is significantly easier than trying to switch later.
A SHIP counselor will compare specific plans for your situation at no cost.
The State Health Insurance Assistance Program provides free, unbiased Medicare counseling in every state. A SHIP counselor can show you specific plan options in your area side by side, based on your doctors, prescriptions, and budget. They do not sell plans and have no financial interest in your decision. Find yours at shiphelp.org.
Part four
Filling in the gaps Original Medicare leaves
If you chose Original Medicare, your coverage has holes. Part A has a deductible for each hospital stay. Part B covers 80 percent of outpatient costs, leaving you responsible for 20 percent with no cap. Medicare Supplement Insurance, called Medigap, is private insurance that covers these leftover costs. Medigap plans are sold by private insurance companies but are federally standardized, meaning each plan letter covers the same things regardless of which company sells it.
You have exactly six months to enroll in Medigap without health questions. After that, in most states, you can be denied.
The Medigap open enrollment window opens the month you are both 65 and enrolled in Part B. During this six-month period, federal law requires every Medigap insurer to sell you any plan without reviewing your medical history or charging you more based on health conditions. Once this window closes, most states allow insurers to reject your application or charge significantly higher premiums if you have health conditions. This window does not reopen. It is one of the most important deadlines in Medicare.
The plan letters
Each letter represents a different level of coverage. The letters are federally standardized, meaning Plan G from Company A covers exactly the same things as Plan G from Company B. You are shopping on price, not benefits, when comparing the same letter across insurers.
G
Covers nearly everything except the Part B deductible. Most popular for new enrollees since 2020.
Most common
N
Lower premium than G. Covers most costs but has small copays for office visits and emergency room.
Good value
F
The most comprehensive plan. Only available to people who turned 65 before January 1, 2020.
C
Similar to F. Only available to people who turned 65 before January 1, 2020.
D
Moderate coverage. Does not cover Part B excess charges.
K
Lowest premium but covers only 50 percent of most costs. Has an out-of-pocket maximum.
L
Covers 75 percent of most costs. Has an out-of-pocket maximum.
M
Covers half the Part A deductible and most other costs.
A
Basic coverage only. Rarely the best value compared to other plans.
B
Adds Part A deductible coverage to Plan A basics.
Most new enrollees in 2025 choose Plan G or Plan N. Plan G covers nearly all out-of-pocket costs after the Part B deductible. Plan N is a lower-premium alternative with small copays for office and emergency visits. To compare prices in your area, use your state insurance commissioner's Medigap comparison tool or ask a SHIP counselor.
1
Choose your plan letter first, then compare prices
Benefits are identical within each letter, so decide which letter fits your needs and then compare the monthly premium for that letter across every insurer selling it in your state. Your SHIP counselor or your state insurance commissioner's website can list all insurers offering each plan in your zip code.
2
Apply directly with the insurance company
Once you have chosen an insurer, you apply directly with them, not through Medicare. During your open enrollment window, the insurer cannot ask about your health or charge you more because of it. The application takes about 15 minutes and coverage typically begins the first of the following month.
3
Keep both your Medicare card and your Medigap card
When you receive care, give providers both cards. Medicare processes the claim first, then your Medigap insurer automatically pays the remainder. You do not need to file separate claims.
If you missed the Medigap open enrollment window, your options depend on your state.
A small number of states provide additional Medigap protections beyond the federal six-month window. Connecticut, Maine, Massachusetts, New York, and a few others require insurers to offer Medigap year-round or with additional guaranteed issue periods. If you are outside your initial window, check your state's specific rules with your state insurance commissioner or a SHIP counselor. In most other states, your realistic options after the window closes are either applying and hoping an insurer accepts you despite your health history, waiting for a qualifying life event that triggers a new window, or choosing Medicare Advantage instead, which cannot deny you based on health conditions during Open Enrollment.
Part five
Making sure your prescriptions are covered
Medicare Part D covers prescription medications through private insurance plans that contract with Medicare. If you chose Original Medicare, you need a separate Part D plan. If you chose Medicare Advantage, drug coverage is usually built in. Either way, enrolling in drug coverage matters even if you take no medications right now.
Skipping Part D creates a permanent penalty even if you take no prescriptions today.
For every month you were eligible for Medicare Part D but went without qualifying drug coverage, Medicare adds a one percent penalty to your Part D premium permanently. If you go without coverage for two years, your Part D premium will be 24 percent higher for the rest of your life. Even if you currently take no medications, enrolling in the lowest-cost Part D plan available in your area protects you from this penalty at minimal cost, typically a few dollars per month.
How to choose and enroll in a Part D plan
1
List every prescription you take, including dose and frequency
Part D plans have formularies, which are lists of which drugs they cover and at what cost tier. The same drug can cost very different amounts under different plans. Having your complete medication list ready makes the comparison meaningful.
2
Use Medicare Plan Finder to compare plans in your zip code
Go to medicare.gov/plan-compare and enter your medications. The tool shows every Part D plan in your area and your estimated annual cost for each based on your specific prescriptions. Sort by estimated annual drug cost, not just monthly premium.
3
Enroll through Medicare Plan Finder or the plan's website
Once you have chosen a plan, enroll directly through Medicare Plan Finder or the plan's own website during your enrollment period. Coverage begins the first day of the following month, or January 1 if you enroll during fall Open Enrollment.
If your income is limited, you may qualify for Extra Help paying Part D costs.
The Extra Help program, also called the Low Income Subsidy, helps people with limited income pay Part D premiums, deductibles, and copays. Many people who qualify do not know it exists. If your annual income is under roughly $22,000 for a single person or $30,000 for a couple in 2025, it is worth applying. People who also have Medicaid qualify automatically. Apply through Social Security at ssa.gov/extrahelp.
Part six
How to know you are done
Medicare enrollment does not come with a single confirmation that everything is complete. Here is what having full coverage in place actually looks like.
Your red, white, and blue Medicare card has arrived
It shows your name, Medicare number, and Part A and Part B start dates. Keep it in your wallet. Guard the Medicare number like a Social Security number.
You have either a Medigap card or a Medicare Advantage card, not both
Original Medicare + Medigap: carry both cards. Medicare Advantage: carry only the Advantage card. Having both a Medigap and Medicare Advantage card means you are paying for redundant coverage.
Your prescriptions are covered
If you have Original Medicare + Medigap, you also need a separate Part D card. If you have Medicare Advantage with drug coverage included, your Advantage card covers prescriptions. Call your plan if you are not sure.
Your primary care doctor accepts your coverage
Original Medicare is accepted by almost any Medicare-accepting provider. Medicare Advantage requires in-network doctors. Call your doctor's office and confirm by plan name. Do not assume - networks change year to year.
When all four are in place, you are enrolled in Medicare.
Your coverage is active, your out-of-pocket exposure is covered, and your prescriptions have a plan. Stage 2 covers what happens once the bills, cards, and letters start arriving.
Free help
Who can help you at no cost
Every decision on this page has a free human expert available to help you make it. None of these resources sell insurance or receive commissions.
Medicare counseling
SHIP. State Health Insurance Assistance Program
Free in every state. Compare plans, understand options, avoid penalties. shiphelp.org
Plan comparison tool
Medicare Plan Finder
Compare Part D and Medicare Advantage plans in your zip code by your medications. medicare.gov/plan-compare
Marketplace plans
Health Insurance Marketplace
If you are still in the waiting period before Medicare begins. Free Navigators available. healthcare.gov
Drug cost help
Extra Help application
If your income is limited, apply for help paying Part D costs. ssa.gov/extrahelp
One more thing
Your coverage is not locked in forever
Once you are enrolled, Medicare gives you one window each year to review and change your coverage. Knowing this date now means you will not be caught off guard when it arrives.
October 15 through December 7 is Medicare's Annual Enrollment Period.
Every year, from October 15 to December 7, you can switch between Original Medicare and Medicare Advantage, change your Medicare Advantage plan, or change your Part D drug plan. Changes take effect January 1 of the following year. This is also the period when Medicare Advantage and Part D plans announce their changes for the coming year, which is why reviewing your plan every fall matters even if nothing in your health situation has changed. A plan that was right for you last year may have changed its premiums, network, or drug formulary.
January 1 through March 31 is the Medicare Advantage Open Enrollment Period.
If you enrolled in a Medicare Advantage plan and want to switch to a different Medicare Advantage plan or return to Original Medicare, you have until March 31 to do so. This period does not allow switching from Original Medicare to Medicare Advantage. Coverage changes from this window take effect the first of the following month.
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