Medicare 101
What actually matters.
Most Medicare guides bury you in coverage details that don't change your decision. This one doesn't. Here's what you actually need to understand — explained the way a licensed agent explains it to a real person sitting across the table.
The Foundation: Medicare Parts A & B
When you turn 65 and enroll in Medicare, you start with what's called Original Medicare — Parts A and B. Think of this as the government-built foundation every Medicare beneficiary stands on.
Part A covers hospital care — inpatient stays, skilled nursing facilities, hospice, and some home health services. For most people, Part A has no monthly premium because you paid into it through payroll taxes while you worked.
Part B covers outpatient care — doctor visits, lab work, preventive care, durable medical equipment, and most things that happen outside a hospital room. Part B does have a monthly premium. In 2026, the standard amount is $202.90 per month.
Original Medicare — A and B together — is actually pretty solid coverage. It covers the vast majority of what happens medically. Most guides spend pages explaining exactly what is and isn't covered, but here's the thing: those details rarely change your decision. What matters is understanding the gaps — and what you do about them.
The Gaps That Actually Matter
Original Medicare has no out-of-pocket maximum. That means if something catastrophic happens — a major surgery, a long hospital stay, a serious illness — there is no ceiling on what you could owe. There's also no coverage for:
- Routine dental care
- Vision (glasses, contacts, routine eye exams)
- Hearing aids and exams
- Most prescription drugs (that's Part D — more on that later)
These gaps are exactly why 99% of Medicare beneficiaries add some form of additional coverage on top of Original Medicare. And that additional coverage is the decision that actually matters.
One more thing worth saying plainly, because most websites won't: Parts A and B are non-negotiable. You must have both to qualify for either a Medicare Supplement or a Medicare Advantage plan — there's no skipping the foundation. As for adding that additional coverage on top? It's not technically required. But going without it is a lot like driving a car with a broken airbag. It's not illegal. Nobody is going to pull you over. But you would be monumentally foolish not to fix it — because the one time you need it and don't have it, no amount of wishing it were different will change what happens next. The financial consequences of going unprotected on Medicare are not theoretical. This guide exists because I've seen them play out in real people's real lives.
The Fork in the Road: Your Two Choices
Once you have Original Medicare as your foundation, you come to the most important decision in your entire Medicare journey. There are exactly two roads you can take — and you can only take one.
"When you come to a fork in the road, take it."— Yogi Berra (and the best way to think about your Medicare decision)
You can either add a Medicare Supplement plan (also called Medigap) that works alongside Original Medicare — or you can replace Original Medicare entirely with a Medicare Advantage plan (also called MAPD or Part C).
You cannot have both. These are two separate roads leading to two different coverage experiences. Neither road is wrong. They suit different people with different priorities, budgets, and lifestyles. The goal of this guide is to make sure you understand both clearly enough to choose the one that fits your life.
Road One: Medicare Supplement (Medigap)
A Medicare Supplement plan — commonly called Medigap — is private insurance that works alongside your Original Medicare. It doesn't replace Medicare. It fills in the gaps Medicare leaves behind: the deductibles, copays, coinsurance, and most importantly, the lack of an out-of-pocket maximum.
The most popular plan is Plan G. With Plan G, after you pay your Part B deductible once per year ($283 in 2026), your Supplement pays virtually everything Original Medicare doesn't. The result is extremely predictable costs — you know almost exactly what healthcare will cost you every month.
What the Supplement experience looks like
You walk into any doctor's office, any specialist, any hospital in the country that accepts Medicare. You show your Medicare card and your Supplement card. That's it. No networks to worry about. No referrals to get. No prior authorizations to fight for. If Medicare approves it, your Supplement pays its share — automatically.
Freedom and predictability come at a price. Supplement plans have a real monthly premium — in North Carolina, a Plan G for someone turning 65 typically starts around $135–$160 per month and increases every year as you age. For some people, that's a comfortable, worthwhile cost. For others, especially those on fixed incomes, it's a significant monthly commitment.
Supplements do not include drug coverage (Part D) or dental, vision, and hearing benefits. Those need to be added separately.
Road Two: Medicare Advantage (MAPD)
A Medicare Advantage plan — also called MAPD or Part C — takes a completely different approach. Instead of working alongside Original Medicare, it replaces it entirely. You're now getting your Medicare benefits through a private insurance company rather than directly from the government.
The best way to understand Medicare Advantage is to think of it like a Costco membership.
When you join Costco, you get access to groceries, pharmacy, dental, vision, optical, tires, travel — everything under one roof at competitive prices. The catch? Those prices and perks are only good at Costco. You can't take your Costco card to Walmart and expect it to work. Medicare Advantage is the same idea: great benefits, often at a low or $0 monthly premium, but you need to use that plan's network of doctors, hospitals, and pharmacies to get those benefits. Step outside the network, and the rules change significantly.
What the Advantage experience looks like
Most MAPD plans come with $0 or very low monthly premiums. They typically bundle in drug coverage (Part D), and many include dental, vision, and hearing benefits — things a Supplement does not cover. Some plans even include gym memberships, transportation to appointments, and over-the-counter allowances.
The trade-off is structure. MAPD plans use networks — HMO or PPO — and most require you to work within them.
"HMOs are bad. PPOs are better because I can go out of network." This is one of the most misunderstood things in Medicare. A PPO gives you the option to go out of network — but the provider still has to agree to accept the plan and bill as out-of-network. Not all of them will. If a doctor declines, you're left with higher in-network cost-sharing and none of the flexibility you thought you were getting. A PPO is only as good as the network of providers willing to use it.
Prior Authorizations — the most important thing to understand about MAPD
Unlike a Supplement, Medicare Advantage plans can require prior authorization — meaning the insurance company must approve certain procedures, tests, or specialist referrals before they happen. This is normal and manageable for most routine care. But it can become a significant friction point for complex medical situations where time and access matter.
This isn't a reason to avoid MAPD plans — millions of people have excellent experiences with them. It's simply something to understand going in so it doesn't come as a surprise.
Supplement vs. Advantage: Side by Side
Neither option is better. They're different tools for different needs. Here's how they compare across the things that matter most:
Medigap / Plan G
- Any doctor or hospital that accepts Medicare — nationwide
- No referrals required
- No prior authorizations
- Very predictable out-of-pocket costs
- Works anywhere in the U.S. — great for travelers
Higher monthly premium ($135–$160+ in NC at 65) that increases each year. Drug and dental coverage must be added separately.
MAPD / Part C
- Often $0 or very low monthly premium
- Drug coverage (Part D) usually bundled in
- Often includes dental, vision, and hearing
- Many plans include gym, OTC allowance, transport
- Annual out-of-pocket maximum provides a safety ceiling
Network restrictions, referral requirements, and prior authorizations. Costs are variable — what you pay depends on what care you use throughout the year.
A common concern about MAPD plans is exposure to large hospital bills. But here's something most Medicare guides don't tell you: a Hospital Indemnity plan can be paired with a Medicare Advantage plan to cover most or all of the cost of a hospital stay — the single largest potential expense on an MAPD plan. For people who want the lower premium of Advantage but also want protection against a big hospital bill, this combination is a legitimate, often overlooked strategy. It doesn't mean you're settling — it means you're planning.
Can You Switch Later? What Most People Don't Know
This might be the most important section in this entire guide. Read it carefully.
Switching from a Supplement back to Medicare Advantage is generally straightforward — you can make that change during the Annual Enrollment Period (AEP) each fall. But going the other direction — from Advantage back to a Supplement — is a different story entirely.
In most states, if you want to switch back to a Medicare Supplement after your initial enrollment window, insurance companies are allowed to medically underwrite you. That means they can review your health history and current health status — and they can decline to cover you or charge you more based on what they find.
Every carrier sets their own underwriting standards, but across most major Supplement carriers, the following are common automatic declines: currently taking a blood thinner (such as Eliquis or Coumadin), using more than 50 units of insulin daily, taking three or more diabetes medications, currently receiving physical or occupational therapy, or having a pending surgery or procedure. This list is not exhaustive — it illustrates how real and specific these standards are.
This doesn't mean switching is impossible — many people do switch successfully, particularly while they are still in good health. The critical point is this: the decision you make at 65, while you're healthy, may become harder to undo at 72 when your health has changed. That's not a reason to pick one plan over the other. It's a reason to make this decision thoughtfully the first time around.
If you're considering Medicare Advantage and wondering whether you could switch to a Supplement later if you need to, the honest answer is: probably — but only if your health allows it. Work with a licensed agent who can help you think through that risk realistically based on your current health picture.
Part D: Drug Coverage — You Need It Even If You Don't Take Anything
Medicare Part D is prescription drug coverage. And here's the single most important thing to know about it:
If you do not enroll in Part D drug coverage when you're first eligible — and you don't have other creditable drug coverage like VA benefits or an employer plan — you will face a late enrollment penalty for every month you went without it. This penalty is added permanently to your Part D premium for as long as you have Medicare. There is no way to remove it, and it grows over time.
Why does it keep growing? Here's the simplest way to think about it: the government sets a benchmark drug coverage price every year — and your penalty is tied to that number. As drug costs rise, that benchmark rises, and your penalty rises right along with it. You don't have to do anything wrong for your penalty to get bigger. Just existing with that penalty attached to your account means it will cost you more every single year, automatically, for the rest of your time on Medicare.
There's another important limitation people often discover too late: you cannot enroll in Part D mid-year simply because your health changes or you start a new medication. Outside of special qualifying life events, enrollment is restricted to specific windows — primarily the Annual Enrollment Period each fall. If you're uninsured for drugs and suddenly need an expensive medication, you may be stuck waiting until the next enrollment period.
Two ways to get Part D coverage
There are two paths to drug coverage, and which one applies to you depends on which road you took at that fork we talked about earlier.
If you chose a Medicare Supplement: Drug coverage is not included. You'll need to add a standalone Prescription Drug Plan (PDP) — a separate plan specifically for medications that works alongside your Supplement and Original Medicare.
If you chose Medicare Advantage (MAPD): Drug coverage is almost always bundled directly into your plan. The "D" in MAPD literally stands for it. In most cases, you don't need to do anything separately.
Drug coverage has more moving parts than almost any other piece of Medicare — drug tiers, formularies, deductibles, the difference between enhanced and standard plans, GLP-1 coverage, therapeutic substitutions, and a 2026 out-of-pocket cap that changes the math for people on expensive medications. All of that lives in our complete Part D guide. For now, just know that you need it, you need to enroll on time, and the plan you pick matters significantly depending on what medications you take.
Where to Go From Here
If you've made it to the end of this guide, you now understand more about Medicare than most people who are already enrolled. That's not an exaggeration — the information in here represents the things a licensed agent walks through with every new client in an initial consultation.
The next step is going deeper on the topics most relevant to your situation. Use the guides below to continue: