How Medicare works, in plain English
Medicare is federal health insurance for people 65 and older, and for some people with disabilities. It comes in four parts, has a handful of enrollment windows that matter a great deal, and gives you a real choice about how you want your coverage to work. This page explains all of it without jargon and without a sales pitch.
Everything here is general education about the Medicare program. It doesn't describe any specific plan or what any plan costs, because those details depend on your county — and that's the part worth a conversation.
Last reviewed: September 2026
The four parts of Medicare
Medicare is a federal health insurance program. It is divided into four parts, and almost every confusing conversation about Medicare comes down to mixing them up. Here is what each one actually is.
Part A
Hospital insurance. Covers inpatient hospital stays, skilled nursing facility care after a hospital stay, hospice, and some home health care.
Most people get Part A at no premium because they or a spouse paid Medicare taxes while working.
Part B
Medical insurance. Covers doctor visits, outpatient care, preventive services, lab work, and durable medical equipment.
There is a monthly premium for Part B. Missing your sign-up window can add a permanent penalty.
Part C
Medicare Advantage. A private plan that replaces Original Medicare and delivers your Part A and Part B benefits, usually through a network.
Many include prescription drug coverage. Rules and costs vary by plan and by county.
Part D
Prescription drug coverage. A separate private plan that covers medications. You can have it alongside Original Medicare, or built into a Medicare Advantage plan.
Part D plans are specific to your county, so what's available depends on where you live.
Parts A and B together are called Original Medicare. When people say "Original Medicare," that is what they mean — the government program itself, with no network. You use it anywhere in the country that accepts Medicare.
The two big decisions most people face are how to handle the costs Original Medicare doesn't pay, and how to get drug coverage. That's where Part C or a Medicare Supplement comes in, and it's the part worth talking through.
Turning 65: the seven-month window
Your Initial Enrollment Period is a seven-month window. It begins three months before the month you turn 65, includes your birthday month, and ends three months after it. Enrolling inside that window is the only way to be certain you avoid a late-enrollment penalty.
Three months before
You can sign up now. Your coverage starts the first day of your birthday month. This is the earliest you can enroll, and it's what most people do.
Your birthday month
Still inside the window. Coverage start dates begin to slip if you enroll here, so it's worth enrolling earlier if you can.
The three months after
You can still enroll, but your coverage start date may be delayed. Enrolling this late can leave you without coverage for a period.
The penalty most people don't know about
If you miss your Initial Enrollment Period and don't qualify for an exception, your Part B premium goes up 10% for every full 12-month period you were eligible for Part B but not enrolled — and in most cases that surcharge stays with you for as long as you have Part B.
There is a legitimate exception that a lot of people use: if you or your spouse is still working and covered by an employer plan based on that active employment, you can usually delay Part B without a penalty. This is one of the very few rules where getting it wrong is expensive, so it's worth a five-minute conversation.
Still working at 65?
Whether you should take Part B depends on the size of your employer and how your coverage works. A general rule of thumb is that coverage from an employer with fewer than 20 employees usually requires you to enroll in Medicare, while coverage from a larger employer may let you delay. That rule has real exceptions, and it's worth checking your specific situation before you decide.
Two more things worth knowing if you're still working: if you delay Part B, you also delay the start of your six-month Medigap Open Enrollment Period — that clock doesn't begin until your Part B does. And if you have a Health Savings Account, enrolling in Medicare affects whether you can keep contributing to it.
Medicare Advantage or Medicare Supplement?
This is the single biggest decision in Medicare, and there is no universal right answer. Medicare Advantage (Part C) replaces Original Medicare with a private plan, usually organized around a network. A Medicare Supplement (Medigap) stays with Original Medicare and pays your share of the costs, with no network of its own. They work in opposite directions, and the choice comes down to your priorities.
| Medicare Advantage (Part C) | Medicare Supplement (Medigap) | |
|---|---|---|
| What it is | A private plan that delivers your Part A and Part B benefits | A private policy that sits alongside Original Medicare |
| Doctors | Usually a network. You check that your doctors are in it. | Any provider nationwide who accepts Medicare |
| Monthly premium | Often lower, and sometimes there is no plan premium beyond Part B | Generally higher, and it is paid on top of Part B |
| Costs as you use care | Copays and coinsurance apply as you receive services | Predictable, because the policy covers your share of covered costs |
| Prescription drugs | Often included in the plan | Not included — you add a separate Part D plan |
| Referrals needed | Sometimes, depending on the plan type | No |
| Travel and out-of-area care | Varies by plan and by whether you're in an emergency | Covers you anywhere Medicare is accepted in the U.S. |
| When you can change | More flexibility — annual windows and an early-year window | Harder after the first six months, especially in Kansas |
| Health questions | Generally none | None during your first six months with Part B; after that, possibly |
The Kansas catch worth knowing before you decide
You get a one-time six-month Medigap Open Enrollment Period that starts the first month you have Part B and are 65 or older. During those six months, an insurer must sell you any Medigap policy it offers — no health questions, no higher price because of your health history.
Kansas does not have a Medigap "birthday rule." Some states give residents a yearly window to switch Medigap plans without underwriting. Kansas is not one of them. Once your six months are gone, a Kansas insurer can ask about your health and can decline you or charge you more.
What that means practically: if there's a real chance you'll want a Medicare Supplement later, the cheapest and easiest time to get one is during that first six months. That window does not come back.
How to actually decide
In my experience the decision usually comes down to four questions, and they're worth answering honestly before you look at any plan:
- Do you want to keep specific doctors? If you have a specialist you see regularly and would not change, that narrows things quickly.
- How do you feel about unpredictable costs? Some people would rather pay more monthly and know what's coming. Others would rather pay less monthly and handle costs as they arise. Neither is wrong.
- Do you travel or spend part of the year elsewhere? Network coverage behaves differently when you're out of your service area.
- What's on your prescription list? Drug costs are where the biggest year-to-year differences hide, and they change every year.
Answer those four and the choice usually becomes obvious. That's the conversation I have with people every day, and it's free.
Prescription drug coverage
Medicare prescription drug coverage is Part D. You get it one of two ways: as a standalone plan you add to Original Medicare, or built into a Medicare Advantage plan. Either way, drug plans are specific to your county, and the plan that is cheapest for one person is often the most expensive for the next person — it depends entirely on which medications you take.
Why your medication list is the most important thing you can bring
Two people in the same ZIP code, on the same plan, can pay wildly different amounts for their prescriptions, because plans sort drugs into tiers and the tiers differ. This is why I ask for your list with dosages before we talk. It is the single fastest way to find out whether an option actually makes financial sense for you.
Two other things worth knowing about Part D:
- Late enrollment has a penalty. If you go without creditable drug coverage for 63 days or more after your initial enrollment period, you may pay a permanent surcharge on your Part D premium when you do enroll. "Creditable" means coverage at least as good as Medicare's standard.
- Drug plans change every year. Formularies change, tiers shift, and premiums move. A plan that was a great fit two years ago may not be now. This is the main reason an annual review is worth twenty minutes.
The enrollment periods, in one table
There are five enrollment periods, and they are constantly confused with each other. Here is what each one is for.
| Period | When it happens | What you can do |
|---|---|---|
| Initial Enrollment Period (IEP) | The seven months around your 65th birthday — three months before, your birthday month, three months after | Sign up for Part A and Part B for the first time, and add Part D or other coverage |
| General Enrollment Period (GEP) | January 1 through March 31 each year | Sign up for Part A or Part B if you missed your Initial Enrollment Period. A late-enrollment penalty may apply. |
| Annual Enrollment Period (AEP), also called Open Enrollment | October 15 through December 7 each year | Join, switch or drop a Medicare Advantage plan, or change your Part D drug plan. Changes take effect January 1. |
| Medicare Advantage Open Enrollment Period | January 1 through March 31 each year | If you're already in a Medicare Advantage plan, switch to a different one or go back to Original Medicare. |
| Special Enrollment Period (SEP) | Varies, based on the situation | Make changes when you have a qualifying event — moving out of your plan's service area, losing other coverage, or a similar change. |
| Medigap Open Enrollment Period | The six months beginning the first month you have Part B and are 65 or older | Buy any Medicare Supplement policy an insurer offers, with no health questions. One time only. |
The one-line version: turning 65 or losing coverage are your open doors. October 15 to December 7 is your annual chance to change your mind. Other than that, you usually need a specific reason.
What Medicare doesn't cover
Original Medicare does not cover long-term custodial care, routine dental, vision and hearing care, or care received outside the United States. These gaps surprise people, and knowing about them in advance is far less expensive than discovering them during a hospital stay.
The big ones:
- Long-term and custodial care. Help with daily activities like bathing, dressing and eating is not medical treatment, and Medicare generally does not pay for it. Skilled nursing facility care is covered only for a limited period and only under specific conditions. This is the most common and most expensive surprise in Medicare.
- Routine dental, vision and hearing. Original Medicare generally does not cover routine cleanings, eye exams for glasses, or hearing aids.
- Care outside the United States. With very narrow exceptions, Original Medicare does not pay for health care you receive abroad.
- Personal care assistance. Help around the house for someone who isn't recovering from an illness or injury is generally not covered.
Some types of Medicare coverage handle parts of these gaps and some don't, which is another reason the coverage-type decision matters. If long-term care is a concern for your family, that is a separate planning conversation from Medicare and worth having deliberately — it's not something Medicare solves.
Notes for Kansas
Kansas has no Medigap birthday rule, which makes your initial six-month window more important here than in some other states. A handful of states let residents change Medicare Supplement plans once a year around their birthday without answering health questions. Kansas is not one of those states. After your one-time six-month Medigap Open Enrollment Period, a Kansas insurer can underwrite you.
Other things that are specifically relevant if you live here:
- Plans are county-specific. What's available in Johnson County is not the same list as what's available a county over. Any comparison has to start with your ZIP code.
- Kansas has a lot of Medigap carriers. That's good news for comparison shopping during your open enrollment window, and it's another reason not to just take the first option you're shown.
- There is free, unbiased help in Kansas. SHICK — Senior Health Insurance Counseling for Kansas — is a state program that provides free Medicare counseling through trained volunteers. Locally, it's administered through the Johnson County Area Agency on Aging. I'll always tell you that option exists, because it's a genuinely good one and you should know about it.
Where I fit: SHICK and I do overlapping work, and I'm glad both exist. SHICK is volunteer-based counseling on a schedule; I'm a licensed agent available on your timeline, and I can enroll you when you're ready. Some people use both. That's completely fine.
Where to get official information
I want you to be able to check everything I tell you. These are the official sources, and I'd rather you use them than take my word for something.
Medicare.gov
The official government site. Use it for the complete list of plans in your ZIP code, drug plan lookups, and official program rules.
1-800-MEDICARE
The official Medicare help line. You can call them for the same complete plan information, and they'll help you enroll directly if you prefer.
1-800-633-4227
1-800-MEDICARE is available 24 hours a day, 7 days a week.
SHICK — Kansas
Free, unbiased Medicare counseling from trained volunteers, coordinated through the Kansas Department for Aging and Disability Services.
Kansas Insurance Department
The state regulator that licenses insurance agents and publishes consumer guides on Medicare Supplement coverage.
You can also verify me. Every insurance agent has a National Producer Number, and Kansas licenses can be checked through the Kansas Insurance Department. My NPN is 20605586 and I'm licensed in Kansas, Missouri, and Texas. If you'd like the license numbers, just ask — I'll send them.
Still not sure which path fits you?
That's the normal reaction. Bring your medication list and the names of your doctors, and we'll work it out in about thirty minutes.