Medicare Parts A, B, C & D, explained in plain English

Medicare gets labeled with letters (A, B, C, and D). Part A and Part B make up Original Medicare. Part C, Medicare Advantage, is another way to receive Part A and Part B benefits through a private plan approved by Medicare. Part D provides prescription-drug coverage through private plans, either as standalone coverage or as part of many Medicare Advantage plans.

The 30-second overview

You'll often hear Part A and Part B together called "Original Medicare." People can keep Original Medicare or receive their Part A and Part B benefits through a Medicare Advantage plan. Part D can be standalone or included in many Medicare Advantage plans.

Part A, hospital insurance

Part A is the hospital side of Medicare. It helps cover inpatient hospital stays, a limited stretch of skilled nursing facility care after a qualifying hospital stay, hospice care, and some home health care. Here's the part people are happy to hear: most folks pay no monthly premium for Part A, because they (or a spouse) paid into Medicare through payroll taxes over roughly ten years of work. Part A still has its own deductibles and limits, but for most people the door to it is essentially pre-paid.

Part B, medical insurance

Part B is the everyday-medical side. It helps cover doctor visits, outpatient care, lab work, preventive screenings, and durable medical equipment like walkers or home oxygen. Unlike Part A, Part B has a monthly premium that the government sets each year (and higher-income households can pay a bit more). Together, Part A and Part B handle a large share of typical medical needs, but they leave some gaps, which is exactly where Parts C and D, or a Medigap policy, come in.

Part C, Medicare Advantage

Part C, better known as Medicare Advantage, is another way to receive your Part A and Part B benefits through a private insurance company approved by Medicare. Many plans include Part D coverage and may offer additional dental, vision, hearing, or fitness benefits. Provider networks, service areas, prior-authorization rules, and costs vary by plan. You must continue paying your Part B premium. For a fuller comparison, see Medicare Advantage vs. Medigap in Florida.

Part D, prescription drug coverage

Part D covers prescription drugs. You can get it as a standalone drug plan alongside Original Medicare or through many Medicare Advantage plans. Each plan has its own formulary, pharmacy network, premium, and cost sharing. A Part D late-enrollment penalty may apply after 63 days in a row without Part D or other creditable drug coverage once your Initial Enrollment Period ends, and it generally continues while you have Part D.

How it fits together: the two paths

Many people choose between these two ways to assemble their coverage:

Path 1, Original Medicare, built out

Start with Part A + Part B, then add a Medigap (Medicare Supplement) policy to help with the out-of-pocket gaps, plus a standalone Part D drug plan. This path tends to mean more freedom to see any doctor who accepts Medicare, with more predictable costs.

Path 2, Medicare Advantage

Choose a Part C (Advantage) plan to receive Part A and Part B benefits. Many plans include Part D and may offer additional benefits. Premiums, networks, cost sharing, prior authorization, and travel coverage vary by plan, and you continue paying the Part B premium.

Neither path is "better" in the abstract, the right one depends on your doctors, your medications, how you travel, and your budget. That's the heart of what I help people sort through.

What Medicare doesn't cover

It's just as useful to know the gaps. Original Medicare generally does not cover routine dental, vision, or hearing care, and it doesn't cover long-term custodial care (the kind of day-to-day help with daily living that nursing homes provide over the long run). Some Medicare Advantage plans include dental, vision, and hearing extras, and there are standalone options too. Knowing these gaps ahead of time is the difference between a plan that looks fine on paper and one that actually fits your life.

A few Florida notes

• The parts are federal; the plans are local. Parts A, B, C, and D mean the same thing nationwide, but which Advantage and Part D plans are available depends on your Florida ZIP code, so any comparison should be run for your specific address.
• Snowbirds, think about travel. If you split the year between states, the nationwide flexibility of Original Medicare plus Medigap can matter more than an Advantage plan's local network.
• New to Medicare? Start with the timing first. My guide to Medicare enrollment periods in Florida shows which window you're in, and how to sign up for Medicare in Florida walks the actual steps.

Quick questions, quick answers

New to all this? Start with my plain-English checklist for Floridians turning 65, or visit the homepage →.