Medicare Parts A, B, C and D Explained

Medicare Parts A, B, C and D are the building blocks of Medicare: Part A helps with hospital care, Part B helps with medical and outpatient care, Part C is Medicare Advantage, and Part D helps with prescription drugs. If you are nearing 65 in Decatur or Central Illinois, the letters can feel like a new language. The good news is that you do not have to sort through them alone.

Book your free 1-on-1 Medicare appointment with Senior Insurance Quote.

Medicare is federal health insurance for people 65 and older and for some younger people with qualifying disabilities or conditions. The important choice is not simply whether to enroll. It is how the parts fit together with your doctors, prescriptions, budget, and comfort level. This guide gives you a plain-language starting point. For a broader overview, see our plain-language Medicare guide for Decatur seniors, then bring your questions to a no-obligation conversation with a local advisor.

What is Medicare, and who can get it?

Medicare is a federal health insurance program. Most people first become eligible at age 65, while some people under 65 qualify because of certain disabilities or conditions. It is individual coverage, so spouses make their own enrollment and coverage choices. You can confirm the basics of eligibility through Medicare.gov’s overview of Medicare parts.

For many Central Illinois families, the confusing part is that Medicare is not one single package. It is a set of coverage choices. Some people use Original Medicare, which includes Parts A and B. Others choose a Medicare Advantage plan, also known as Part C, from a private company approved by Medicare. Prescription drug coverage, Part D, is another choice to consider.

A quick way to remember the Medicare parts

• Part A: hospital and inpatient care.

• Part B: doctor visits, outpatient care, preventive care, and medical equipment.

• Part C: Medicare Advantage, a private-plan alternative that combines Part A and Part B coverage and usually includes Part D.

• Part D: prescription drug coverage through a private plan.

Those letters describe coverage categories, not a one-size-fits-all answer. The right setup can depend on the doctors you see, the medicines you take, whether you travel, and which plans are available where you live.

Medicare Part A: hospital coverage

Medicare Part A helps cover inpatient care in hospitals, skilled nursing facility care, hospice care, and some home health care. It is often called hospital insurance. Part A is not the same as coverage for every service that happens inside a hospital. Medicare rules, deductibles, coinsurance, and length-of-stay requirements can still matter.

Many people qualify for premium-free Part A because they or a spouse paid Medicare taxes while working. The Social Security Administration notes that Part A is free for people who worked and paid Medicare taxes for at least 10 years. That does not mean all Part A care is free, so it is wise to understand the cost-sharing rules before a hospital stay whenever possible.

What Part A commonly helps with

• Inpatient hospital care

• Skilled nursing facility care when Medicare requirements are met

• Hospice care

• Limited home health care

Part A is one reason Original Medicare can be a solid foundation, but it is only one piece of the picture.

Medicare Part B: medical and outpatient coverage

Medicare Part B helps cover doctor visits, outpatient care, preventive services, ambulance services, and durable medical equipment. It covers the day-to-day medical care that Part A does not.

Part B has a monthly premium. In 2025, the standard Part B premium is 85 per month. Most people pay this standard amount, although higher-income beneficiaries pay more through Income-Related Monthly Adjustment Amounts. There is also an annual deductible of 57 for 2025, after which you typically pay 20% coinsurance for most covered services.

What Part B commonly helps with

• Doctor and specialist visits

• Preventive services, including annual wellness visits and screenings

• Outpatient hospital services

• Ambulance services

• Durable medical equipment such as walkers, wheelchairs, and oxygen equipment

• Mental health services, including partial hospitalization

Part B is the part of Medicare that most directly touches your everyday healthcare, which is why it is important to understand both what it covers and what it does not.

Medicare Part C: Medicare Advantage (a private-plan alternative)

Medicare Part C, also called Medicare Advantage, is a private-plan alternative to Original Medicare. Private insurance companies approved by Medicare offer these plans. When you join a Medicare Advantage plan, Medicare pays the private insurer a fixed amount to manage your care. In exchange, the plan must cover everything Original Medicare covers, except hospice care (which Part A still covers).

Most Medicare Advantage plans bundle Part A, Part B, and often Part D into one plan. Many also include extra benefits such as routine dental, vision, and hearing coverage, gym memberships, meal delivery after a hospital stay, and even transportation to medical appointments. However, Advantage plans typically have restricted provider networks, meaning you may need to see in-network doctors and may need prior authorization for certain services.

What Part C commonly offers

• All Part A and Part B coverage combined in one plan

• Often includes Part D prescription drug coverage

• Extra benefits like dental, vision, hearing, wellness programs, and more

• Annual out-of-pocket maximums that limit your total spending

• Network-based care, usually HMO or PPO plans

Medicare Part D: prescription drug coverage

Medicare Part D helps cover the cost of prescription drugs. Private insurance companies offer Part D plans, and you must be enrolled in Part A or Part B to qualify. Part D plans have their own monthly premiums, annual deductibles, copayments, and coverage phases.

Understanding the Part D coverage phases can help you avoid surprises at the pharmacy. In 2025, the coverage phases include the deductible phase, initial coverage phase, and the catastrophic coverage phase. Once you reach the catastrophic phase, your out-of-pocket costs drop significantly for the rest of the year.

What Part D commonly covers

• Most generic and brand-name prescription drugs

• Each plan has its own formulary (list of covered drugs)

• Tiered pricing, with lower copays for generics and higher copays for brand-name and specialty drugs

Part D is optional, but if you do not sign up when you are first eligible and do not have other creditable drug coverage, you may owe a late-enrollment penalty for as long as you have Part D coverage. An independent broker can help you compare Part D plans to find one that covers your medications at the lowest cost.

Medigap: filling the gaps in Original Medicare

Medigap, also called Medicare Supplement Insurance, is private insurance that helps pay some of the out-of-pocket costs that Original Medicare does not cover, such as deductibles, coinsurance, and copayments. Medigap pairs with Original Medicare (Parts A and B). It does not cover Part D drug costs, and it cannot be used with Medicare Advantage.

Medigap plans are standardized across insurers and identified by letter (Plan A, Plan B, Plan G, Plan N, and so on). The benefits for each lettered plan are the same regardless of which insurance company sells it. However, premiums vary by company and by where you live. The best time to buy a Medigap policy is during your Medigap Open Enrollment Period, which starts when you turn 65 and enroll in Part B. During this time, you cannot be turned down or charged more due to pre-existing conditions.

What Medigap commonly helps with

• Part A coinsurance and hospital costs up to an extra 365 days after Medicare benefits are used

• Part A deductible

• Part B coinsurance or copayment

• Part B excess charges (some plans)

• Foreign travel emergency care (some plans)

How an independent local broker makes the difference

Reading about Parts A, B, C, D, and Medigap can feel overwhelming. That is where an independent broker like Senior Insurance Quote makes the difference. With over 40 years of experience and access to more than 35 insurance carriers, Juliette Chihade and her team help Central Illinois seniors compare plans side by side.

There is no charge to meet with us. Whether you prefer to sit down in person, talk by phone, or include a family member in the conversation, you are welcome here. We take the time to understand your doctors, prescriptions, and budget, then show you the options that fit.

Why choose Senior Insurance Quote

• Independent broker serving Decatur since 1981

• Access to over 35 insurance carriers

• 5-star Google rating

• Free, no-obligation consultations and annual reviews

• Personal service from Juliette Chihade, a local expert

Schedule your free appointment today. You will leave with a clear understanding of the Medicare parts and a plan that works for you.