Turning 65 brings a short stack of Medicare decisions that arrive more or less all at once, and the order you make them in matters as much as the answers. Most of the expensive mistakes people make are not bad choices. They are good choices made a few months too late, or in the wrong sequence, after a window has quietly closed. This guide walks the decisions in the order they actually come up, names the deadline attached to each one, and tells you which ones you can revisit and which ones you cannot.
The short version is this. Start about seven months before your birthday. Decide whether to take Part B now or delay it because you are still working. Then face the one genuinely large decision — Original Medicare with a supplement and a drug plan, or a single Medicare Advantage plan — knowing that one path leans on a six-month window that never comes back. Everything else is detail around those anchors. We will take them one at a time, with the 2026 numbers where they matter.
Start seven months out
Your first Medicare decision is not what to choose. It is when to act, and the answer is earlier than most people expect.
The window to first enroll in Medicare is called the Initial Enrollment Period, and it lasts seven months. It runs from three months before the month you turn 65, through your birthday month, and for three months after. Seven months feels generous, and that feeling is exactly the trap. The length of the window is not the point. The point is that when inside it you act determines when your coverage begins.
Here is the mechanic that catches people. If you enroll during the three months before your birthday month, your coverage starts on the first day of your birthday month — the first day you are actually eligible, with no gap. If you wait until your birthday month or the three months after, your start date is pushed back. You will have used the window, technically, but you will have bought yourself a stretch of time with no Medicare coverage in force. If something happens during that stretch, you pay for it out of pocket.
So the single most useful thing to understand about the Initial Enrollment Period is that its back half is a fallback, not a plan. Treat the first three months — the ones before your birthday month — as the real deadline.
If you take one action from this entire article, make it this: act in the three months before your birthday month, not after.
There is a practical reason to start even earlier than the window opens: the decisions below take time to think through, and some of them are difficult or impossible to reverse. Giving yourself a couple of months of runway to compare options is not over-preparation. It is the difference between choosing calmly and choosing under a deadline. The official Medicare.gov site is the place to confirm your own dates, and it is worth doing early rather than assuming.
One note on how you enroll
If you are already receiving Social Security benefits before 65, you are usually enrolled in Parts A and B automatically, and your card simply arrives. If you are not yet drawing Social Security, enrollment is not automatic — you have to sign up yourself, through Social Security. A surprising number of gaps come from people assuming the card would just show up. Confirm which situation you are in before the window opens.
Decision 1: Take Part B now, or delay it?
Medicare has parts. Part A covers inpatient hospital care and is premium-free for most people, because they or a spouse paid into it through payroll taxes for long enough. Because it is free, most people simply take Part A at 65 and there is nothing to decide.
Part B is different. It covers doctor visits, outpatient care, and much of the rest of routine medicine, and it carries a monthly premium — $202.90 in 2026. That premium is the reason the first real decision exists: do you take Part B now, or delay it?
For most people retiring at or before 65, the answer is straightforward. You take it, because you need the coverage and there is no other insurance in the picture. The decision only becomes live if you are still working at 65 and have health coverage through your job, or through a spouse’s job.
The rule that protects a delay
Whether you can delay Part B without a permanent penalty depends on two things: the size of the employer and whether the coverage is creditable. Broadly, if the employer is large enough and the coverage is at least as good as Medicare, you can usually delay Part B safely, and a Special Enrollment Period opens when the job or the coverage ends, letting you sign up then without penalty.
If the employer is small, the picture can flip entirely. Medicare may become the primary payer at 65 whether or not you have enrolled — which means your employer plan may quietly stop being your main coverage, and you could be far less insured than you think without anything visibly changing.
This is the part of the whole process where guessing is most expensive, because the Part B late-enrollment penalty is added to your premium for as long as you have Part B. It is not a one-time fee. So this is the one decision to confirm in writing — with your benefits administrator and with Social Security — rather than infer from a forum post or a well-meaning coworker. The rules turn on the specifics of your employer and your coverage, and those specifics are knowable. Get them in hand before you decide.
For most people who are fully retiring at 65, none of this applies: you take Part B, and you move on to the decision that actually shapes your coverage.
Decision 2: The big fork
This is the decision that matters most, and it is the one people spend the least time on. Once you have Parts A and B, you choose how to fill the gaps they leave — because Original Medicare on its own does not cover everything, and, importantly, it has no annual out-of-pocket maximum. Without something layered on top, your exposure in a bad year is theoretically unlimited.
There are two roads out of this, and they run in different directions.
Road one: Original Medicare, plus a Medicare Supplement, plus a Part D drug plan. You keep Original Medicare and add a Medicare Supplement policy — also called Medigap — that pays most of the cost-sharing Original Medicare leaves behind. Because a supplement does not include prescriptions, you add a standalone Part D drug plan alongside it. You pay a higher, predictable monthly premium, you can use any provider in the country that accepts Medicare, and there is no network to worry about. For people who travel, split the year between states, or simply want to remove surprises, this predictability is the appeal.
Road two: a Medicare Advantage plan. A Medicare Advantage plan (sometimes called Part C) bundles your Part A, Part B, and usually Part D into one plan run by a private insurer. Premiums are often low, sometimes zero on top of your Part B premium, and many plans add extras Original Medicare does not cover. In exchange, you use the plan’s provider network, you pay copays as you go, and your costs are capped by an annual out-of-pocket maximum rather than covered up front. Medicare Advantage has grown into the majority choice: roughly 35 million people — about 55% of eligible beneficiaries — were enrolled as of early 2026, according to KFF.
How to think about the fork
Neither road is better in the abstract. They are different trade-offs:
- Cost shape. A supplement front-loads your cost as a steady premium and minimizes what you pay when you actually use care. Advantage lowers the premium and asks you to pay copays as you go, up to a yearly cap.
- Access. A supplement lets you see any Medicare provider anywhere. Advantage ties you to a network, which is a real consideration if you have established specialists or spend part of the year elsewhere.
- Simplicity. Advantage is one card and one plan. Original Medicare plus a supplement plus Part D is three moving pieces to set up, though it runs quietly once it is in place.
There is one more thing about this fork that most comparison content leaves out, and it is the reason the order of these decisions matters. Choosing Advantage is easy to walk back in one direction — you can generally return to Original Medicare during the right window. What is not guaranteed is being able to pick up a supplement afterward, because by then you may have to pass medical underwriting. That asymmetry is the entire reason the next decision exists.
Decision 3: The one-time Medigap window
If there is a single sentence in this guide worth reading twice, it is this one: the window to buy a Medicare Supplement with no health questions asked happens once, lasts six months, and never returns.
It is called your Medigap Open Enrollment Period, and it begins the month your Part B coverage starts. During those six months, an insurer cannot decline you for a supplement and cannot charge you more because of your health history. Your medical record is, for this one window, invisible to the underwriter. You are guaranteed acceptance.
After it closes, that guarantee is gone. Most supplement applications, in most circumstances, are then medically underwritten — the insurer reviews your health and can say no, or charge more. There are limited guaranteed-issue rights in narrow situations, but they are exceptions, not a strategy you can plan around.
This is why the fork in the previous section is not a decision you can comfortably defer. If you lean toward Medicare Advantage at 65 partly because it is cheaper, understand what you may be spending in exchange: the easy, guaranteed path into a supplement later. People discover this at the worst possible moment — after a diagnosis, when an Advantage plan’s network limits have suddenly become a real problem, and when their health now makes a supplement hard to obtain or unaffordable.
None of this makes Medicare Advantage a mistake. For many people it is the right choice, made deliberately. The mistake is choosing it without knowing that the supplement door does not stay open. Make the decision with the window in view, not in hindsight.
The six-month Medigap window is the only Medicare window that never repeats. Everything else you can revisit. This one you cannot.
Decision 4: Part D and its penalty
Prescription drug coverage is the decision people most often talk themselves out of, and it is the one with a penalty that follows you the longest.
If you go the Original Medicare and supplement route, prescriptions are not included — you need a standalone Part D plan. If you choose Medicare Advantage, drug coverage is usually built in. Either way, the point is to have creditable drug coverage in place, and to have it from the start.
Here is where the reasoning goes wrong. Plenty of people reach 65 taking no medications at all, look at a Part D premium, and reasonably conclude they do not need it yet. The logic is understandable and it is expensive. If you go 63 or more days in a row without creditable drug coverage after your Initial Enrollment Period ends, a late-enrollment penalty is added to your Part D premium — and that penalty is permanent. It is not a one-time catch-up cost. It is added to your premium for as long as you have Part D, and it grows the longer you went without.
Drug coverage is priced as insurance against future need, not as a bill for current prescriptions. Declining it because you are healthy today creates a permanent surcharge on the plan you will almost certainly want later. The projected average standalone Part D premium for 2026 is about $34 per month, per Medicare.gov and CMS — modest next to a penalty you would carry for the rest of your life.
There is a genuine improvement worth knowing here too. Starting in 2025, Part D gained an annual cap on what you pay out of pocket for covered drugs, and for 2026 that cap is $2,100. Once you reach it, your plan pays 100% of covered drug costs for the rest of the calendar year. Before 2025 there was no ceiling at all. For anyone on an expensive medication, that cap is one of the most significant changes to Medicare in years, and it is another reason not to skip Part D at the start.
What it costs in 2026
Numbers change every year, and 2026 brought a noticeable step up in the Part B figures. Here is where the fixed costs stand, straight from CMS.
| Item | 2026 | 2025 |
|---|---|---|
| Standard Part B premium | $202.90/month | $185.00/month |
| Part B annual deductible | $283 | $257 |
| Part A hospital deductible | $1,736 per benefit period | $1,676 |
| Part D out-of-pocket cap | $2,100 | $2,000 |
| Projected average Part D premium | ~$34/month | ~$38/month |
Source: CMS 2026 Parts A & B fact sheet. Figures are for plan year 2026 and were reviewed on August 4, 2026.
A few things to read out of that table. The standard Part B premium rose $17.90 for 2026, and the deductible rose $26 — meaningful increases worth budgeting for. Higher-income beneficiaries pay more than the standard premium through an income-related adjustment (IRMAA), which in 2026 begins above $109,000 for an individual and $218,000 for a married couple filing jointly. If your income is below those thresholds, the standard premium is what applies to you.
The Part A hospital deductible of $1,736 applies per benefit period, not per year, which is a distinction that surprises people. And remember the point from the fork: Original Medicare has no annual out-of-pocket maximum of its own. The premiums above are the fixed, knowable part of your cost. What you owe on top of them, in a year where you actually need care, is exactly what a supplement or an Advantage plan’s out-of-pocket cap is there to contain. For a fuller look at what shifted this year, see our companion piece on 2026 Medicare costs and what changed.
We do not quote specific plan premiums here on purpose. Supplement and Advantage premiums vary by plan, insurer, and where you live, and any number we printed would be out of date or wrong for your situation. The figures above are the ones set nationally by CMS and are the same for everyone.
The windows at a glance
Three enrollment windows do most of the work in your first year on Medicare. They are easy to confuse because two of them run on the calendar and one runs on your birthday — and the one that runs on your birthday is the one that never comes back.
| Window | When it opens | What it lets you do | Repeats? |
|---|---|---|---|
| Initial Enrollment Period (IEP) | 3 months before your birthday month → birthday month → 3 months after (7 months total) | Enroll in Parts A and B, and add Advantage or Part D. Act in the first 3 months to avoid a coverage gap. | No — once, at 65 |
| Medigap Open Enrollment | The month your Part B starts, for 6 months | Buy a Medicare Supplement with no health questions and guaranteed acceptance | No — once, never returns |
| Annual Enrollment Period (AEP) | October 15 – December 7 each year | Join, switch, or drop a Medicare Advantage or Part D plan; changes take effect January 1 | Yes — every year |
The pattern to hold onto: the two windows you can lean on later are the Annual Enrollment Period every fall and the Medicare Advantage Open Enrollment that follows it each January through March. The one you cannot get back is the six-month Medigap window. Line your decisions up so you are not spending that window while you are still deciding.
Window timing per Medicare.gov.
If you live in Wisconsin
If you are in Wisconsin — as many of the people we work with are, since our home base is northeast Wisconsin — one part of this guide works differently, and it is worth flagging before you start comparing supplements.
Wisconsin is one of only three states (along with Massachusetts and Minnesota) that does not use the federal Medigap system of lettered plans, Plan A through Plan N. These are sometimes called waiver states. Instead, Wisconsin standardizes its Medicare Supplement policies its own way, built around a basic policy that insurers add optional riders to. The practical consequence is simple but important: a national comparison site quoting you a premium for “Plan G” is quoting a plan that is not sold in Wisconsin. The mechanics those sites describe do not map onto what you can actually buy here.
Everything else in this guide still applies to Wisconsin residents without change. The seven-month Initial Enrollment Period, the Part B decision, the six-month Medigap window with no health questions, the Part D penalty — all identical. It is only the shape of the supplement plans themselves that differs. So if you are in Wisconsin, discount the national plan-letter content when you compare supplements, and start from state-specific material instead. If you are in one of the other states we serve — Florida, Michigan, North Carolina, Virginia, Kentucky, or Maine — the federal lettered plans apply as normal.
The decisions in order
Pulling it together, here is the sequence, with the deadline attached to each step.
- About seven months before your birthday, start. Confirm your dates on Medicare.gov and check whether you will be enrolled automatically or need to sign up through Social Security yourself.
- In the three months before your birthday month, enroll in Part A and B — unless you are delaying Part B for creditable employer coverage. Acting in this first stretch of the Initial Enrollment Period is what keeps your coverage gap-free.
- Decide the Part B question deliberately. If you are still working, confirm in writing whether your coverage lets you delay without penalty. If you are retiring, take Part B.
- Make the big fork with the Medigap window in view. Original Medicare plus a supplement plus Part D, or a Medicare Advantage plan — chosen knowing that the supplement door is only guaranteed open once.
- If you want a supplement, use the six-month Medigap window. It starts when Part B starts, it asks no health questions, and it never repeats.
- Put creditable Part D drug coverage in place from the start, either standalone or built into an Advantage plan, to avoid the permanent late penalty.
- After year one, use the calendar windows. Each fall’s Annual Enrollment Period (October 15 – December 7) lets you adjust your Advantage or Part D plan as your needs and the plans change.
Most Medicare mistakes are not decisions made badly. They are windows that closed while someone was still thinking it over. Getting the order right is most of the battle.
How we help
You do not have to sort this alone, and there is no fee to have someone walk it through with you. We can lay your seven-month window against the calendar, work out whether delaying Part B is safe in your specific situation, and compare the Medicare Advantage, Medicare Supplement, and Part D options actually available where you live — including the Wisconsin-specific supplements the national sites get wrong. The goal is a decision you understand and can live with, made before any window closes, not after.
If you are approaching 65, the best time to have that conversation is a few months out, while every door is still open. Book a no-fee review and we will map your decisions in order, with your dates and your 2026 numbers in front of us.
We do not offer every plan available in your area. For a complete list of options, contact Medicare.gov, call 1-800-MEDICARE, or reach your State Health Insurance Assistance Program (SHIP). Benefits Empire is an independent agency and is not connected with or endorsed by the U.S. government, the federal Medicare program, or CMS.
This article is educational and is not tax, legal, or investment advice. Medicare figures change annually — always verify current premiums, deductibles, and deadlines at the official source before you decide. Prepared with Dani Jo Munger, NPN 19254421.