March 30th 2026
By Ari Parker
Medicare Coverage & Insurance Plan Options: Parts A, B, C, D, and Medigap Explained
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March 30th 2026
By Ari Parker
When you first become eligible for Medicare, it can feel like you've been handed a puzzle with no picture on the box. There are parts, plans, letters, and acronyms—and the stakes are high. But here's the truth: Medicare doesn't have to be this complicated. Once you understand how the pieces fit together, the picture becomes much clearer.
This guide walks you through every Medicare coverage option available to you: Parts A, B, C, and D, plus Medigap (also called Medicare Supplement). By the end, you'll know exactly what each part covers, what it costs, and how they work together to protect your health and your wallet.
Original Medicare is the foundation of your coverage. It includes Part A and Part B, both funded by the federal government and available to every American over the age of 65—along with some Americans with disabilities and certain chronic conditions. About 93% of doctors across the country accept Original Medicare, making it the most universally accepted health insurance program available to older Americans.
Here's the most important thing to know about Original Medicare upfront: it covers about 80% of your healthcare costs. That leftover 20% is yours to manage—and that's exactly why additional coverage options exist.
Medicare Part A is your inpatient coverage. If you're admitted to a hospital for at least one night, Part A is what kicks in. It also covers skilled nursing facility care, hospice care, and some home health services.
The good news: Part A is free for most Americans who have worked and paid Medicare taxes for at least 10 years (and their spouses). For most people, this one is a no-brainer—it's there when you need it, at no additional cost.
What Part A covers:
Inpatient hospital stays
Skilled nursing facility care (following a qualifying hospital stay)
Hospice care
Some home health services
If Part A is your hospital coverage, Part B is everything else—the day-to-day outpatient care that keeps you healthy. Think doctor visits, lab work, preventive screenings, and durable medical equipment.
What Part B covers:
Doctor and specialist visits
Outpatient services and surgery
Ambulance services
Durable medical equipment
Preventive care and screenings
Part B does come with a monthly premium. In 2026, the standard cost is $202.90/month—an increase of nearly 10% from 2025—though high earners may pay more due to IRMAA surcharges. The annual Part B deductible is $283 in 2026. And just like Part A, there can be a penalty for signing up outside of your Initial Enrollment Period unless you qualify for a Special Enrollment Period.
Together, Part A and Part B make up Original Medicare—your starting point for everything else.
Here's where most people get tripped up. Original Medicare covers 80% of your costs—which sounds solid until you do the math. If you have a major surgery or a serious illness, 20% of your medical bills can add up to tens of thousands of dollars. For older Americans living on fixed incomes, that kind of financial exposure is a real risk.
This is exactly why additional Medicare coverage options exist. You have two main paths forward:
Medigap (Medicare Supplement) — Stacks on top of Original Medicare to cover most or all of that remaining 20%
Medicare Advantage (Part C) — Replaces Original Medicare entirely with a bundled plan from a private insurer
And regardless of which path you choose, you'll also want to consider Part D for prescription drug coverage.
Medicare Advantage—also known as Part C—is an alternative way to receive your Medicare benefits. Instead of going through the federal government, your coverage comes through a private insurance company that contracts with Medicare. By law, every Medicare Advantage plan must cover at least everything that Original Medicare covers. Most go further, bundling in Part D (prescription drug coverage) and extras like dental, vision, and hearing benefits.
What Medicare Advantage often includes:
All Part A and Part B benefits
Prescription drug (Part D) coverage
Dental, vision, and hearing benefits
Perks like gym memberships, flex spending cards, meal delivery, and transportation
2026 Medicare Advantage fast facts: The average monthly premium for Medicare Advantage plans dropped to around $14 in 2026, down from $16.40 in 2025. Over 99% of Medicare beneficiaries have access to at least one Medicare Advantage plan, and 97% have 10 or more plan options to choose from.
What to watch out for:
Many Medicare Advantage plans advertise $0 premiums, which sounds appealing—but that doesn't make them free. You're still on the hook for your Part B premium. And while the monthly costs may be lower than Medigap, you'll likely face higher out-of-pocket costs when you actually use your insurance.
Medicare Advantage plans also use provider networks, which means you may be limited in which doctors you can see. If you split time between two homes or travel frequently, this can be a significant drawback. Most plans also require prior authorization for more expensive services—and prior authorization denials are far too common, even when care is medically necessary.
Every Medicare Advantage plan is different, and the details matter enormously. Before enrolling in any plan, make sure your doctors are in-network and your prescriptions are covered.
Original Medicare doesn't cover prescription drugs. That's where Part D comes in.
You can get Part D coverage two ways: as a stand-alone prescription drug plan (if you're on Original Medicare) or bundled within a Medicare Advantage plan. Either way, the coverage works the same—but the costs and what's covered can vary significantly from plan to plan.
Every Part D plan has a formulary—a list of covered drugs organized into tiers. Lower-tier drugs (usually generics) cost less. Higher-tier drugs cost more. Before enrolling in any plan, it's critical to check that your specific prescriptions are covered and to compare what you'll owe at the pharmacy.
2026 Part D fast facts:
The average monthly premium for a stand-alone Part D plan is around $34.50 in 2026—actually down from 2025, thanks to a federal premium stabilization program
Many people can find plans with $0 premiums
56% of Medicare beneficiaries get their Part D coverage through a Medicare Advantage plan
The out-of-pocket cap on Part D drug costs is $2,100 in 2026 (up slightly from $2,000 in 2025)
Insulin copays remain capped at $35/month, and recommended vaccines are covered at no cost
Don't skip Part D—even if you don't take prescriptions now. If you go more than 63 days without creditable drug coverage after becoming eligible, you could face a Part D late enrollment penalty that sticks with you for as long as you have coverage. The penalty is calculated as 1% of the national base beneficiary premium ($38.99 in 2026) for every uncovered month—and it compounds over time. The smartest move is to enroll when you're first eligible, even if you're healthy.
One more thing worth knowing: if you have a lower income, you may qualify for Medicare's Extra Help program (also called the Low-Income Subsidy). Extra Help can cover your Part D premiums, deductibles, and coinsurance—and it waives the late enrollment penalty entirely.
If you stay on Original Medicare, Medigap is the most powerful tool you have to protect yourself from that 20% gap. Medigap plans—also called Medicare Supplement plans—sit on top of your Original Medicare coverage and pick up most or all of what's left over.
There are 10 standardized Medigap plan types, labeled A through N. Here's what makes Medigap unique: every plan of the same type must provide identical coverage, regardless of which insurance company sells it. If you buy Plan G from one company, it covers the same things as Plan G from any other company. The only difference is the price—which is why it pays to shop around.
The biggest advantages of Medigap:
Predictable costs. With a comprehensive Medigap plan like Plan G, you'll rarely be surprised by what you owe at the doctor's office. You pay your premium, and most of your costs are covered. For people who value financial certainty, this peace of mind is invaluable.
See any doctor who accepts Medicare. Because Medigap has no provider networks, you can see any of the roughly 93% of doctors nationwide who take Original Medicare. This is a major advantage for travelers, snowbirds, and anyone who wants maximum flexibility in their care.
No prior authorization. With Original Medicare and Medigap, you never need to get prior authorization for covered services. You need care, you get care—full stop.
What Medigap doesn't cover:
Medigap covers what Original Medicare doesn't—but Original Medicare itself doesn't cover dental, vision, hearing, or prescriptions. That means those gaps remain. If you're on Medigap, you'll need a separate Part D plan for prescriptions and separate coverage for dental, vision, and hearing if you want those benefits.
A word on enrollment timing:
Your Medigap Open Enrollment Period is a six-month window that begins when your Part B coverage starts. During this window, you're guaranteed acceptance into any Medigap plan regardless of your health history. Once that window closes, you can still apply for Medigap—but you may need to go through medical underwriting, and you could be denied or charged more based on your health. This makes timing your enrollment carefully one of the most important decisions you'll make in Medicare.
There's no single "best" Medicare plan—but there is a best plan for your specific health needs, finances, and lifestyle. Here's a simple way to think about it:
Original Medicare + Medigap Plan G + Part D is widely considered the most comprehensive Medicare coverage available. It gives you the broadest access to doctors, the most predictable out-of-pocket costs, and solid prescription coverage. It does come with higher monthly premiums, which isn't the right fit for everyone.
Medicare Advantage (Part C with Part D included) can be a smart choice for people who want lower monthly premiums and don't mind working within a provider network. The perks—dental, vision, gym memberships—are real benefits. Just go in with eyes open about the potential for higher out-of-pocket costs and prior authorization hurdles when you need care.
The decision between these paths is one of the most consequential financial and health decisions you'll make in retirement. It deserves more than a 15-minute phone call with an agent who's focused on one plan or one carrier.
At Chapter, we help older Americans understand, choose, and use their Medicare—with unbiased advice that puts your needs first. Our licensed Medicare Advisors will ask about your doctors, your prescriptions, and your budget, then compare every plan available to you to find the one that fits.
Our advice is always free. Give us a call at (855) 900-2427 or schedule a free consultation to get your questions answered and feel confident in your Medicare decisions.
