If you're new to Medicare, the first thing to know is that almost everyone finds it confusing. Not because you're missing something, but because it genuinely is more complicated than it needs to be. The system was built in pieces over sixty years, and each piece was named after a letter of the alphabet, and the letters do not spell anything useful. So let's walk through what's actually going on.
What Medicare actually is
Medicare is the federal health insurance program for people 65 and older, plus some younger folks with disabilities or specific conditions. It's run by the Centers for Medicare & Medicaid Services (CMS), funded mostly by a combination of payroll taxes and premiums, and it's been around since 1965.
The federal government does not directly pay your doctor for everything Medicare covers. Some parts they do, some parts they contract out to private insurance carriers. Which is exactly where the confusion comes from.
The four Parts
Medicare is divided into four parts: A, B, C, and D. Two of them (A and B) are the original program, run by the federal government. Two of them (C and D) are run by private carriers but regulated by Medicare.
Part A is hospital insurance. If you're admitted to a hospital, hospice, or a skilled nursing facility, Part A pays. Most people get Part A for free because they paid into Medicare through payroll taxes during their working years (you need 40 quarters of work credit, which is about ten years).
Part B is medical insurance. This covers doctor visits, outpatient procedures, lab work, and durable medical equipment like wheelchairs. Part B has a monthly premium that almost everyone pays — in 2026, the standard premium is around $185 per month, with higher amounts for higher-income enrollees.
Together, Part A and Part B make up what's called Original Medicare. If you stop here and don't add anything else, you've got coverage for hospital and medical, but with notable gaps: there's no prescription coverage, no dental, no vision, no hearing, and Part B leaves you on the hook for 20% of most outpatient costs with no annual cap.
That's where Parts C and D come in.
Part C is Medicare Advantage. This is a private alternative to Original Medicare — instead of getting your coverage from the federal program directly, you enroll in a plan offered by a private carrier (Humana, Aetna, UnitedHealthcare, and so on) that's contracted with Medicare to provide your benefits. Advantage plans bundle Parts A and B together, almost always include Part D drug coverage, and often add extra benefits like dental, vision, and gym memberships. The trade-off is the network: Advantage plans have a defined set of doctors and hospitals you stay within.
Part D is prescription drug coverage. It's run by private carriers but regulated by Medicare. You can buy a standalone Part D plan to pair with Original Medicare, or you can get drug coverage rolled into a Medicare Advantage plan.
The two paths
Once you understand the four parts, the actual decision boils down to two paths.
Path one: Original Medicare plus extras. You stay on Parts A and B. You add a Part D drug plan. You optionally add a Medicare Supplement (also called Medigap) plan to cover the deductibles and coinsurance that Part B leaves on the table. This path costs more per month in premiums but gives you nationwide flexibility — any doctor that accepts Medicare accepts your Supplement plan.
Path two: Medicare Advantage. You sign up for a Part C plan from a private carrier. The plan bundles your Part A, Part B, and usually Part D coverage, often with extra benefits thrown in. This path usually costs less per month — many Advantage plans have $0 premiums beyond your Part B premium — but ties you to a specific network of providers.
Neither path is universally better. The right choice depends on where you live, who your doctors are, what prescriptions you take, how much you travel, and how predictable you want your annual costs to be.
What does NOT come with Medicare
Worth saying explicitly: routine dental, vision, and hearing care are not covered by Original Medicare. Long-term custodial care (the kind people often associate with nursing homes) is not covered. Care received outside the United States is mostly not covered. If those gaps matter to you, you're looking at either a Medicare Advantage plan that includes some of these benefits, or standalone dental/vision/hearing plans, or in some cases a separate long-term care insurance policy entirely.
When you can sign up
You become eligible for Medicare on the first day of the month you turn 65. Your Initial Enrollment Period is a seven-month window: the three months before your 65th birthday month, the birthday month itself, and the three months after. Sign up during that window and you usually avoid late-enrollment penalties.
If you miss your Initial Enrollment Period and don't have other qualifying coverage, you may have to wait until the General Enrollment Period (January 1 – March 31 each year) to sign up, with coverage starting the month after enrollment. You'll likely pay a late-enrollment penalty for as long as you have Medicare.
After enrollment, you can change your plan during the Annual Enrollment Period every fall (October 15 – December 7). And there's a separate Medicare Advantage Open Enrollment Period (January 1 – March 31) for folks already on an Advantage plan to switch.
What to do next
If you're approaching 65, you don't need to figure all of this out alone. A licensed Medicare agent can walk you through your specific situation — your zip code, your doctors, your prescriptions — at no cost to you. The carriers pay our commissions, not you.
A first call usually takes 15 to 30 minutes. We won't try to enroll you on the call. We'll just lay out your options, send you a written summary, and let you decide on your own time. That's what we'd want for our own parents — and that's the standard we're trying to hold for everyone.