Open enrollment mail is piling up, and the pitchforks are out.
On one side you have Medicare Advantage, the all-in-one plan with $0 premiums and extras like dental and gym memberships.
On the other, Medigap supplements that cost real money each month but cover what original Medicare leaves behind.
The difference between these two paths can swing thousands of dollars a year, and most people pick based on the brochure instead of the math.
Original Medicare pays 80% of most covered costs after deductibles, and you cover the rest with no annual cap.
A supplement, also called Medigap, picks up most or all of that remaining 20% and caps your exposure.
Medicare Advantage replaces original Medicare with a private plan that usually has a network, prior authorizations, and an annual out-of-pocket maximum that can run into the thousands.
Advantage premiums can be zero, but the plan still takes its payment from the government, and that money comes out of the same pool that funds everyone's Medicare.
A 2024 analysis estimated taxpayers spend roughly 20% more per person on Advantage than on traditional Medicare.
That gap doesn't show up on your statement, but it shows up somewhere.
Then there's the prior authorization problem.
An investigation by federal watchdogs found that some Advantage plans denied requests that should have been covered, and a share of those denials got reversed on appeal.
If you or a parent has ever spent a week on the phone fighting for a rehab stay, you understand the emotional tax.
Supplements don't play that game because they follow Medicare's rules.
A Medigap Plan G for a 65-year-old can run $120 to $200 a month depending on the state.
That's a real line item next to rising rent and credit card APRs.
Advantage looks cheaper until you land in the hospital, hit a $5,000 or $8,000 out-of-pocket max, and realize the "savings" vanished in one bad quarter.
The right answer depends on whether you can absorb a surprise bill or would rather pay a predictable premium.
The catch with supplements is that you can be denied.
Outside your initial enrollment window, and in most states, a Medigap insurer can reject you or charge more because of your health history.
That asymmetry is why advisors say the choice at 65 is close to permanent, and why switching later gets expensive.
If you travel a lot, see specialists at big hospitals, or want the fewest surprises, a supplement plus a drug plan is often the safer structure.
If you're healthy, live near a strong local network, and need every dollar now, Advantage can work.
Compare the out-of-pocket maximum, the drug formulary, and the network before you compare the premium.
My take: treat the $0 premium as a marketing number, not a price.
Write down your worst-case year for both options, then choose the one you could actually pay for.
Final Thoughts
The plan that protects your savings is the one worth the monthly cost.