One choice shapes which doctors you can see, what you pay and how many pieces you manage: Original Medicare with a Medigap policy and a Part D plan, or a Medicare Advantage plan that bundles everything. Here are both paths with 2026 numbers, and the window that makes the first choice hard to reverse.
The two paths in one view
| Path 1: Original Medicare + Medigap + Part D | Path 2: Medicare Advantage (Part C) | |
|---|---|---|
| Core coverage | Part A and Part B, run by the government | Part A and Part B, delivered by a private insurer |
| The 20% coinsurance and deductibles | Paid by a Medigap policy | Replaced by the plan's copays up to its out-of-pocket maximum |
| Drug coverage | A separate Part D plan, capped at $2,100 out of pocket in 2026 | Usually built in, with the same $2,100 cap |
| Providers | Any doctor or hospital that accepts Medicare | The plan's network, with referrals and prior authorization |
| Extras (dental, vision, hearing) | Not included | Often included |
| Monthly premiums | Part B ($202.90 in 2026) + Medigap + Part D | Part B ($202.90) + the plan's premium, often $0 |
Path 1 buys freedom and predictability with steady premiums; Path 2 buys simplicity and a low premium with networks and pay-as-you-go costs.
Path 1: Original Medicare with a Medigap policy
Original Medicare alone leaves you the Part A deductible ($1,736 per benefit period), the Part B deductible ($283) and then 20% of every approved bill with no annual cap. A Medigap policy (Medicare Supplement Insurance) pays most of what is left.
Medigap plans are standardized by letter: a Plan G from any insurer covers everything Original Medicare leaves except the $283 Part B deductible, and a Plan N is cheaper with small copays for some office and emergency visits. Because coverage is identical for a given letter, you compare price and service; premiums vary by insurer, age and ZIP code, and medicare.gov's plan finder lists them.
The appeal is freedom — no network, any provider that takes Medicare, anywhere in the country — and predictability: with Plan G you pay premiums and the $283 deductible and almost nothing else. The price is the Medigap premium on top of Part B, plus a Part D premium.
Path 2: Medicare Advantage
A Medicare Advantage plan bundles Part A, Part B and usually Part D into one private plan, often with dental, vision or hearing extras, for a plan premium that is frequently $0 on top of Part B.
The trade-offs are structural: care is covered within the plan's network (an HMO or PPO), many services need a referral or prior authorization, and you pay copays as you use care up to the plan's in-network out-of-pocket maximum, set by each plan under a federal ceiling. A healthy year costs little; a heavy year costs up to the cap. Plans change every year, so read the Annual Notice of Change each fall.
The windows that make the choice sticky
| Window | When | What it lets you do |
|---|---|---|
| Medigap open enrollment | The 6 months starting the first month you have Part B at 65 or older | Buy any Medigap policy sold in your state with no health questions |
| Medicare Open Enrollment | October 15 to December 7 each year | Switch between Original Medicare and Advantage, or change Advantage or Part D plans |
| Medicare Advantage Open Enrollment | January 1 to March 31 each year | Switch Advantage plans once, or drop Advantage for Original Medicare plus a Part D plan |
The triangle
| What you value most | Points toward |
|---|---|
| Any provider, anywhere | Original Medicare + Medigap |
| Predictable costs in a heavy year | Original Medicare + Medigap |
| The lowest monthly outlay | Medicare Advantage |
| Dental, vision or hearing built in | Medicare Advantage |
| The lowest total cost in a healthy year | Medicare Advantage |
Path 1 pays for certainty and freedom every month; Path 2 pays as you go and asks you to accept a network. The costs lesson covers the gaps neither path fills.