Understanding Key Medicare Terms: A Beginner’s Glossary
- Monica Pineider
- 3 days ago
- 4 min read
Medicare can feel like a foreign language when you first look into it. With all the unfamiliar phrases, acronyms, and rules, it’s easy to feel overwhelmed. But don’t worry—you’re not alone. Many people find Medicare confusing at first. Once you learn the basics and understand some key Medicare terms, it makes much more sense.
This guide will help you get comfortable with the most common Medicare terms. It’s meant for beginners, so everything is written in plain, simple language.

What Is Medicare?
Before we dive into the glossary, let’s take a step back and understand what Medicare is.
Medicare is a federal health insurance program in the United States. It’s mainly for people 65 and older, but younger people with specific disabilities or severe health conditions (like end-stage kidney disease) can also qualify.
Medicare helps cover many health care costs. That includes doctor visits, hospital stays, preventive services, and prescription drugs. But it’s not entirely free. You may still have to pay deductibles, premiums, copayments, or coinsurance.
Understanding your options and the Medicare terms associated with them is key to making the right choices.
Table of Contents
What Are Medicare Terms?
Medicare terms are the official words and phrases used to explain how the Medicare system works. They appear in your plan documents, enrollment forms, letters, and websites. If you don’t know what they mean, it’s easy to get lost.
This glossary is designed to help you understand each term clearly, one at a time.
Annual Enrollment Period (AEP)
This is a set time when you can change your Medicare plan each year. It runs from October 15 to December 7. During the AEP, you can:
Switch from Original Medicare to a Medicare Advantage Plan
Switch back to Original Medicare
Change your Part D drug plan
Drop coverage altogether
Outside of this time, changes are limited—unless you qualify for a Special Enrollment Period.
Beneficiary
A beneficiary is a term indicating a person who receives Medicare benefits. Once you’re enrolled, that means you.
You’ll see this word in official letters and forms. It’s just the formal way to say “the person getting coverage.”
Coinsurance
Coinsurance is your share of the costs for a medical service. It’s not a fixed fee—it’s a percentage.
Let’s say Medicare pays 80% of your bill. You’d pay the other 20%. This cost-sharing typically applies after you’ve met your deductible.
Copayment (Copay)
A copay is a flat fee you pay for certain services. For example, it might be $20 for a doctor's visit or $10 for a prescription.
Unlike coinsurance, it doesn’t change based on the total bill. Copays are standard in Medicare Advantage and Part D plans.
Deductible
A deductible is a term that indicates the amount you pay before Medicare starts helping. It’s like a spending threshold.
For example, if your deductible is $240, you must pay that amount first. After that, Medicare begins to share the cost of your care.
Formulary
This is a list of prescription drugs your Medicare plan covers. Every Part D and Medicare Advantage Plan has its formulary.
The list may include generic and brand-name drugs. It’s usually divided into “tiers,” which affect your cost. Always check the formulary to ensure your medications are covered before choosing a plan.
Medicare Advantage Plan (Part C)
This term indicates a private insurance plan that offers an alternative to Original Medicare. It bundles Part A (hospital) and Part B (medical), often including extras.
Many Advantage Plans also cover Part D (prescription drugs), dental, vision, and hearing. However, you must use the plan’s network of doctors and hospitals.
Some people prefer these plans for convenience and extra services.
Medicare Part A
Part A covers hospital-related services, including inpatient care, skilled nursing facilities, hospice, and home health care.
Most people get Part A for free if they pay Medicare taxes while working. Although it covers big expenses, there are still deductibles and coinsurance.
Medicare Part B
Part B is your outpatient medical coverage. It pays for doctor visits, lab tests, preventive care, mental health services, and durable medical equipment.
Part B has a monthly premium. It’s essential if you want coverage for everyday care that doesn’t involve a hospital.
Medicare Part D
Medicare Part D is a term indicating prescription drug coverage. It can be a standalone plan or part of a Medicare Advantage Plan.
Each plan has its formulary and pricing. Costs can vary depending on your prescriptions and where you live.
Medigap (Medicare Supplement Insurance)
Medigap is extra insurance sold by private companies. It helps pay for things Original Medicare doesn’t fully cover, like:
Copays
Coinsurance
Deductibles
Medigap plans don’t include drug coverage or extras like dental or vision. They’re only available to people with Original Medicare, not Medicare Advantage.
Premium
A premium is the amount you pay every month to stay covered. Most people pay a Part B premium. You’ll also pay premiums for other plans, like Part D or Medicare Advantage.
The cost depends on your income and the plan you choose.
Special Enrollment Period (SEP)
A Special Enrollment Period lets you sign up for or change plans outside the standard enrollment windows.
You may qualify for an SEP if:
You move to a new state or area
You lose other insurance
You leave your job or retire
Your plan changes its service area
Each SEP has different rules about when and how you can make changes. It’s a safety net for when life changes suddenly.
Final Thoughts
Learning Medicare terms is a smart first step. It helps you feel more confident when reviewing plans or talking to insurance providers.
If you’re still unsure, that’s okay. Tools like Healthpilot help you compare Medicare plans side by side. They make finding a plan matching your budget and health needs easier.
Navigating Medicare doesn’t have to be hard with the proper knowledge and support.