Medicare
Turning 65 hands you one of retirement’s biggest decisions: Original Medicare with a Medigap supplement, or a Medicare Advantage plan. Getting it right the first time matters, because switching later can be difficult or expensive.
What Original Medicare covers — and what it doesn’t
Original Medicare has two parts. Part A covers hospital care and is premium-free for most people. Part B covers roughly 80% of outpatient care for a monthly premium that rises with income. Prescription drugs require a separate Part D plan.
The catch: Original Medicare on its own has no cap on out-of-pocket costs, and it doesn’t cover dental, vision, hearing, care outside the U.S., or long-term care. That uncapped 20% is why nearly everyone pairs it with something else.
Option 1: Medicare Advantage (Part C)
Advantage plans are private plans that bundle Parts A and B, usually include drug coverage, and often add perks like dental, vision, or gym memberships — frequently for a low or $0 premium on top of Part B. They also set an annual out-of-pocket maximum, which Original Medicare lacks.
The trade-offs are structural: you’re limited to a provider network, referrals and prior authorizations are common, coverage can be denied as not “medically necessary,” and costs can climb quickly if you become seriously ill. And if you later want to switch to Medigap, you may face medical underwriting and be declined or charged more.
Option 2: Original Medicare + Medigap
Medigap (supplemental) policies are standardized, lettered plans that pay the gaps in Original Medicare. With a comprehensive plan like Plan G, nearly everything beyond the small Part B deductible is covered by premiums: no networks, no referrals, and you can see any doctor in the country who accepts Medicare.
The cost: meaningfully higher monthly premiums over a lifetime, separate Part D shopping, and no dental/vision extras. For people in poor health — or who simply want cost certainty and maximum flexibility — it is often the cheaper option in the years that matter most.
The timing rules that protect you
Two windows deserve a calendar reminder. Your Medigap open enrollment is the six months starting with your Part B effective date: during it, you can buy any Medigap plan with no medical underwriting. And if you try Medicare Advantage at 65, you have a 12-month trial period to switch back without underwriting. Miss those windows and your options can narrow permanently. Also review your coverage every fall — networks and drug formularies change yearly.
Key takeaways
- Advantage plans are usually cheaper up front; Medigap usually wins on flexibility and worst-case costs.
- Original Medicare alone has no out-of-pocket cap — pair it with something.
- Your first enrollment windows are the most protected time to choose; use them deliberately.
Sources
Plan structures and enrollment rules summarized from Medicare.gov and educational materials published by Vanguard on Medicare choices. Free, personalized help is available from your State Health Insurance Assistance Program (SHIP).