If you're somewhere between 64 and 66 and starting to look at Medicare, you've probably already noticed the problem. There's too much information out there, most of it is written by someone trying to sell you something, and very little of it explains what's actually going on.
I've been helping St. Louis folks sort this out since 2013. The goal of this article is simple: in about ten minutes, give you a clean picture of what Medicare actually is, what the four parts do, and what to do next. No sales pitch. Just the map.
What Medicare actually is
Medicare is the federal health insurance program for people 65 and older, and for some people under 65 who have qualifying disabilities or end-stage renal disease. It's run by the government — the Centers for Medicare & Medicaid Services, or CMS — and most people qualify automatically when they turn 65 because they paid into it through payroll taxes during their working years.
It's not a single plan. It's a system of four parts (A, B, C, and D), and the choices you make about those parts shape what you pay and which doctors you can see for the rest of your life. That sounds dramatic. It is.
The four parts — in plain English
Here's the whole system in one paragraph. Part A covers hospital stays. Part B covers doctor visits and outpatient care. Everybody has to have A and B — that's your base. Part C (Medicare Advantage) is a private plan that combines everything you need into one plan. It typically includes your Part D drug coverage and extras like dental, vision, hearing, and a gym membership. Part D covers prescription drugs. That's it. Everything you'll read on Medicare.gov, everything an advisor tells you, every plan comparison — it's all decisions about those four parts.
Now the details.
Part A
Hospital InsuranceInpatient hospital stays, skilled nursing rehab after a hospital stay, hospice, and some home health care. Premium-free for most people who paid Medicare taxes for at least 40 quarters. A per-benefit-period deductible of $1,736 in 2026 if you're admitted, plus coinsurance for long stays.
Part B
Medical InsuranceDoctor visits, outpatient care, preventive services, lab work, durable medical equipment. Monthly premium of $202.90 in 2026 for most people; higher earners pay more (see IRMAA). Annual deductible of $283 in 2026. Medicare covers 80% after that — with no out-of-pocket maximum, which is why most folks add a Supplement or an Advantage plan.
Part C
Medicare AdvantageA private plan that delivers your Part A and Part B benefits instead of Original Medicare — you keep A and B; the plan just becomes how you use them. Most bundle in Part D drug coverage plus extras like dental, vision, and hearing. Some have $0 plan premiums (Part B will still have a cost). Advantage plans use networks — which matters a lot in St. Louis.
Part D
Prescription Drug CoverageDrug coverage, either as a stand-alone plan added to Original Medicare, or bundled into an Advantage plan. Monthly premium varies by plan, with a list (a "formulary") of which drugs the plan covers and at what tier. New: an annual out-of-pocket cap on Part D drug costs — $2,100 in 2026 (it began at $2,000 in 2025 and is indexed for inflation) — the old "donut hole" no longer works the way it used to.
How Medicare works in St. Louis
Most of Medicare is the same in every state. But three things matter more here than they do in smaller markets.
The plans you can choose depend on your county
Medicare Advantage and Part D drug plans are sold county by county. Medicare calls the area a plan covers its “service area,” and to join one you have to live inside it — so the list of plans you can actually pick from, along with their premiums, networks, and extras, depends on which county you live in. That matters more here than in a lot of places. St. Louis City and St. Louis County are two separate jurisdictions (the City has been independent, part of no county, since 1876), so their plan lists aren't identical — and as you move out to St. Charles, Jefferson, or Franklin, or across the river into Illinois (Madison, St. Clair, Monroe), the choices can change a lot. It's worth confirming what's actually available where you live before you fall for a plan your friend in the next county recommended. (Medicare Supplement plans work differently — they're not tied to a county or a network, so a Medigap policy works with any provider nationwide who takes Medicare.)
Hospital networks
St. Louis has four big hospital systems — BJC HealthCare (Barnes-Jewish, Christian, Memorial East, Missouri Baptist, St. Louis Children's, Progress West, and others), Mercy, SSM Health, and SLUCare Physician Group. If you choose a Medicare Advantage plan, you'll be on a network — and not every plan covers every system. The single most common mistake we catch in our office is somebody who already enrolled in a plan and didn't realize their primary care doctor was out of network. Confirm before you enroll.
The Missouri Medigap anniversary rule
Missouri has one of the friendlier rules in the country for Medicare Supplement (Medigap) plans. Every year around the anniversary of your Supplement policy, you have a window to switch to a same-letter plan from a different carrier without going through medical underwriting. Most states don't allow that. It means you don't have to pick the perfect Supplement carrier on the first try. We cover the rule in detail in a separate article — for now, just know it's an advantage of being a Missourian.
When to sign up
Your Initial Enrollment Period (IEP) is a 7-month window: the three months before the month you turn 65, the month you turn 65, and the three months after. If you sign up before the month you turn 65, your coverage usually starts the first day of your birthday month. If you sign up later in the window, coverage starts later — and if you miss the window entirely, you may face a permanent late-enrollment penalty added to your Part B premium for the rest of your life.
There are exceptions. If you're still working past 65 and have qualifying group coverage, the rules are different and the deadlines shift. (See our Working Past 65 article for the full picture.)
Our shortest piece of advice: don't try to sign up the same week your IEP closes. Give yourself room. Pick up the phone and call Medicare or a licensed agent eight or nine months out.
How to choose between Original Medicare and Advantage
This is the biggest decision you'll make, so I want to be careful with it. Here's the honest version.
Original Medicare + a Supplement + a Part D plan ("the three pieces") gives you the most freedom. You can see any doctor in the country who accepts Medicare. You'll have predictable monthly costs (premium for Part B + premium for the Supplement + premium for Part D), and the Supplement covers most or all of what Medicare doesn't. It tends to cost more per month and doesn't usually include dental or vision.
Medicare Advantage (Part C) bundles everything together — typically a lower (or $0) monthly plan premium (Part B will still have a cost), includes drug coverage, often includes dental and vision extras, includes an out-of-pocket maximum. The tradeoff comes down to two things: the network, and the fact that these are managed-care plans. Plans are designed around specific hospital systems and provider groups, and your costs are higher if you go outside the network. And because it's managed care, the insurance company has a say in your care — which doctors are in-network, when a referral or prior approval is needed. Original Medicare doesn't work that way.
Which one is right for you depends on three things: your doctors (who are you not willing to leave?), your prescriptions (which plans cover them affordably?), and your travel and lifestyle (do you spend three months in Florida every winter?). There's no one-size-fits-all answer, and I'd be lying if I said there was.
We sell both, and we'll tell you which one fits you. If the answer is "neither one we offer is right for you," we'll tell you that, too. There's a whole separate article on the Advantage-vs-Supplement decision if you want to keep going.
Common mistakes St. Louisans make
Five we see often:
- Picking a plan based on the monthly premium alone. A "low premium" plan can cost thousands more per year if it doesn't cover your specific prescriptions or your specific doctors.
- Assuming Medicare Advantage covers everything everywhere. It doesn't. Networks matter.
- Skipping the drug list comparison. Most mistakes come from this. Bring the names and doses of every prescription you take to every conversation.
- Missing the Part B late-enrollment deadline. The penalty is permanent. It's 10% of the standard Part B premium for each full 12 months you were eligible but didn't sign up, added to your premium for life. At the 2026 premium of $202.90, one full year late adds about $20.29 per month; two years late, about $40.58.
- Assuming COBRA lets you put off Part B. Here's the part that trips people up: COBRA drug coverage is usually creditable for Part D, so on the drug side you're often fine. But COBRA does not count for Part B — it won't let you delay it without a penalty, and it gives you no Special Enrollment Period when it ends. Sign up for Part B on time anyway.
What to do next
If you still have months before your IEP starts, you have time. Download our free Turning-65 Medicare Checklist (St. Louis Edition) — it's a week-by-week guide that walks you from six months out to your start date. Or call us at (314) 248-6500. No fee, no pressure, no sales pitch — that's the rule of the house. We answer every call.
If you're inside your IEP, the same offer stands, just with more urgency. A 30-minute conversation usually answers everything.
We're a family team here in St. Louis, and I've been helping people with Medicare since 2013. The whole reason we built this Learning Center is so you can come prepared — not because you have to.
