A few months before a 65th birthday, the mail changes. Glossy folders, urgent deadlines, a parade of letters — A, B, C, D — plus words like Medigap and Advantage that sound like they should mean something obvious and don't. If your parent has handed you the pile and said you're good at this stuff, this guide is for you. None of it is as complicated as the mail makes it look. There is really one vocabulary lesson, one genuine decision, and a couple of deadlines that matter more than everything else combined.
The four letters, in one minute
Part A is hospital insurance — it helps cover inpatient stays and some care that follows them. Part B is everything outpatient: doctor visits, tests, procedures that don't involve being admitted. After a deductible, Part B typically pays about 80% of approved costs; the remaining share is your parent's unless something else picks it up. Part D is prescription drug coverage, sold by private insurers. Together, A and B are what people mean by Original Medicare.
Part C is the confusing one, because it isn't another slice of the pie — it's a different way of getting the whole pie. Better known as Medicare Advantage, it's a private plan that bundles A and B, usually includes drug coverage, often adds extras like dental or vision, usually comes with a network of doctors, and — importantly — caps how much your parent can pay out of pocket in a year.
And Medigap isn't a part of Medicare at all. It's a private supplement that pairs with Original Medicare and covers much of the cost-sharing — that 20%, the deductibles. One rule to tattoo somewhere: Medigap works only with Original Medicare. It cannot be combined with a Medicare Advantage plan.
The real choice underneath the alphabet
Strip away the marketing and there are two roads, each a fair trade honestly made:
- Original Medicare + Medigap + Part D. Your parent can see essentially any doctor in the country who takes Medicare — no networks, no referrals — and Medigap makes costs predictable. The price of that freedom is paying more in premiums, month after month, whether or not care is needed.
- Medicare Advantage. Usually lower premiums, one card, extras, and a hard annual ceiling on out-of-pocket costs — something Original Medicare, without Medigap, doesn't have at all. The price is networks and plan rules: the doctors have to be in-network, and some care needs the plan's approval first.
Which trade is right depends on the parent, not the plan. Someone who splits the year between two states, or who has a specialist relationship they'd protect at any cost, tends to value the flexibility road. Someone whose doctors are all local and in-network, and for whom the monthly premium is the number that hurts, may be genuinely well served by Advantage. There is no universally correct answer — but there is a catch about switching later, which brings us to the part people regret not knowing.
The timing traps
Medicare punishes lateness more than it punishes almost anything else. Three windows to respect:
- The initial enrollment window, around the 65th birthday. Missing it (without qualifying coverage from a job) can mean late-enrollment penalties on Parts B and D — surcharges that don't quietly go away.
- The one-time Medigap window. For six months after Part B starts, insurers must sell your parent a Medigap policy regardless of health history. After that window closes, in most states they can decline or charge more based on health. This is the asymmetry that matters: moving from Medigap to Advantage is easy; moving back later is not guaranteed. "Try Advantage now, get Medigap when we're older and need it" is exactly the plan the rules frustrate.
- Open enrollment each fall, when Advantage and drug plans can be changed for the coming year. Not a trap so much as an opportunity people sleep through — which deserves its own section.
The one-afternoon fall review
Plans change every year, quietly. Each fall your parent's plan mails an annual notice of change, and it is worth actually reading, because "we've updated your plan" can mean a drug moved to a pricier tier or a beloved doctor left the network. Here is the whole ritual, one afternoon in October, coffee included:
- Line up the pill bottles. Check each prescription against the plan's drug list — the formulary — for next year. A plan that was the cheap choice last year can be the expensive one this year for the exact same medications.
- Call the roll of doctors. Is the cardiologist still in-network? The eye doctor? Networks shift annually.
- Run the plan finder at medicare.gov with the real drug list and real pharmacies. Twenty minutes, and it compares actual yearly costs rather than premiums alone.
If nothing changed and the plan still fits, wonderful — you've spent an afternoon buying a year of peace of mind.
Where to get help that isn't selling anything
Much of the "help" that arrives in the mailbox is commission-based, which doesn't make it dishonest — it just means you should know whose interests are in the room. Two sources have no horse in the race: medicare.gov, the official plan finder, and SHIP — the State Health Insurance Assistance Program — which offers free, one-on-one counseling from trained volunteers in every state. A SHIP counselor will sit with your parent's actual medications and doctors and walk the options without earning a dime from the answer. For the conversation about being invited into these decisions in the first place, our guide to talking with a parent about money applies here almost word for word.
Where FamSteady fits: these are exactly the questions the care navigator was built to answer — not with generic articles, but with your family's context. Ask it "does Mom's plan choice matter if she winters in Arizona?" or "what should we check before open enrollment?" and it answers the way a knowledgeable friend would, and tells you when a question deserves a SHIP counselor or a real person instead.
What is the simplest difference between Medigap and Medicare Advantage?
Medigap works alongside Original Medicare and helps pay the leftover cost-sharing, and your parent usually keeps the freedom to see any provider who accepts Medicare. Medicare Advantage replaces the way they receive Part A and B benefits with a private plan, usually with a network and often with bundled extras. One is a supplement; the other is an alternative package.
Can someone have Medigap and Medicare Advantage together?
Generally no. Medigap is designed to work with Original Medicare. If a person enrolls in Medicare Advantage, Medigap typically doesn't cover the Advantage plan's cost-sharing and may be discontinued under the applicable rules. Before anyone changes coverage, confirm the current rules with Medicare.gov or a SHIP counselor.
Does Original Medicare cover prescriptions?
Parts A and B generally don't cover most outpatient prescription drugs. People usually add a separate Part D plan, or get drug coverage through a Medicare Advantage plan that includes Part D. Either way, check the formulary for the specific medications your parent takes, because coverage varies from plan to plan.
How should families compare plans without pressure?
Start with your parent's priorities, their current doctors, and their prescriptions, then use the official comparison tools or a free SHIP counselor. Write the tradeoffs in plain language so everyone can look at them again later. Ignore sales urgency. Your parent decides; the rest of the family helps by asking questions and taking notes.
What is Open Enrollment in plain English?
It's a yearly window when most people with Medicare can review and change certain coverage choices for the following year. The dates and rules vary depending on the situation, so check the current guidance on Medicare.gov rather than going by what happened last year.
Is Medicare Advantage the same as a Medicare Supplement?
No. "Medicare Supplement" usually means Medigap. Medicare Advantage is Part C, an all-in-one way to receive Medicare benefits through a private plan. Mixing up the two labels on a phone call is a common way to end up with the wrong paperwork and a delay, so it's worth being precise.
Where can we get unbiased help?
Start with Medicare.gov and your state's SHIP program, which offers free counseling. Licensed agents can help too; ask who they represent and how they're paid. FamSteady's Care Navigator is meant to help families keep their benefits questions organized, and it doesn't replace official advice or a licensed professional.
