Medicare Advantage vs. Medigap: The Decision Adult Children Actually Have to Help With

When a parent turns 65, or during open enrollment, the family hits the same fork: Medicare Advantage or Medigap (Medicare Supplement)? Both are valid, both have millions of members, and both hide costs that only show up later. This page is the plain-English difference, who each one fits, and the five questions to answer before choosing.

Last reviewed August 2026 Reading time: 7 minutes

the trade is freedom against price

The Medigap vs Advantage ledger

Medigap pays the gaps in Original Medicare; Advantage replaces it with a private plan. The ledger shows who each fits, and the one question that matters most is the worst month, not the premium.

QuestionMedigapAdvantage
DoctorsAny doctor who takes Medicare, no networkNetwork only; check the parent's actual doctors
CostsHigher monthly premium, small or no copaysLower or $0 premium, per-visit costs add up
Worst yearStrongest protection against a serious-illness yearReal out-of-pocket maximum, but it can be very high
ExtrasUsually none (dental, vision, hearing are separate)Often includes dental, vision, hearing, gym
The windowGuaranteed-issue at 65 or the open window: buy then or lose itCan switch later, but leaving may be hard

The rule, in one sentence: Medigap pays the gaps in Original Medicare and lets a parent see any doctor who takes Medicare; Medicare Advantage replaces Medicare with a private plan that has a network and extra benefits. The trade is freedom and predictability against lower premiums and extras.

The one-paragraph difference

Original Medicare (Parts A and B) is the federal baseline: it covers hospital and doctor care, with deductibles and coinsurance you pay yourself. Medigap is a private policy sold alongside Original Medicare that pays those gaps, so the parent's out-of-pocket cost becomes predictable and small. Medicare Advantage (Part C) is the other route: instead of Original Medicare plus a supplement, the parent enrolls in a private insurance plan that must cover everything Medicare covers, usually with a network of doctors, a lower monthly premium, and extra benefits (dental, vision, hearing, sometimes gym memberships) that Original Medicare does not cover.

Both are real choices. Neither is a scam, and neither is "wrong" for everyone. The mistake families make is choosing on premium price alone, because the two options shift costs in opposite directions.

How the money actually works (this is the part everyone gets wrong)

  • Medigap: pay Medicare Part B premium (everyone pays this), plus a Medigap premium (typically $100 to $300 a month depending on plan and age), plus the Part D drug plan premium. In exchange, most medical costs are covered with small copays or none. The predictability is the point: a parent who gets seriously ill is protected from huge bills.
  • Medicare Advantage: pay the Part B premium (usually), often a $0 or low plan premium, and then copays and coinsurance per visit, procedure, and hospital day. The premium looks better; the out-of-pocket per service is higher, and there is an annual out-of-pocket maximum (which is a real protection, but it can be very high).

The honest frame: Medigap costs more per month and protects against the worst year. Advantage costs less per month and makes every visit cost something. For a parent on a fixed budget with regular care needs, the "cheaper" Advantage plan can end up costing more; for a healthy parent who rarely sees a doctor, Advantage's lower premium can genuinely win.

Who each one fits

Medigap fits parents who:

  • Want to see any doctor who takes Medicare (no network), especially if they travel or see specialists.
  • Want predictable costs and the strongest protection against a serious-illness year.
  • Are willing to pay a higher monthly premium for that freedom.
  • Are enrolling at 65 or within their Medigap open-enrollment window, when insurers cannot refuse them for health reasons. This window matters enormously: after it, Medigap can be much harder to get.

Medicare Advantage fits parents who:

  • Are comfortable with a network and fine with choosing in-network doctors.
  • Want the extra benefits (dental, vision, hearing) and a lower premium.
  • Live in one area, do not travel much, and have predictable, low care needs.
  • Understand the per-visit costs and the out-of-pocket maximum, and can budget for them.

The five questions to answer before choosing

  1. Which doctors does the parent actually see, and do they take each option? Call the two or three most important doctors' offices and ask directly. A plan with the wrong network is a plan with hidden costs.
  2. What are the parent's real prescriptions? Part D drug coverage is separate from both choices. Check the specific drugs against each plan's formulary; the same drug can cost very different amounts. See Medicare for adult children for the parts-level basics.
  3. How much travel and how many specialists? Medigap follows the parent anywhere Medicare works; Advantage networks can leave a traveling parent with big out-of-network bills.
  4. Can the parent afford the worst month? Compare the annual out-of-pocket maximum of the Advantage plan against what a bad year under Medigap would actually cost. The number that matters is the worst case, not the average.
  5. Is the parent still in a Medigap guaranteed-issue window? If yes, that is the moment the Medigap door is open wide. If the parent already missed it, Advantage may be the practical choice, because Medigap may be medically underwritten and expensive or unavailable.

When the answer is "talk to a real expert"

This page gives you the map, not the terrain: premiums, networks, and formularies change every year and differ by county. Two free, official, no-commission sources: the Medicare plan comparison tool (see Sources) shows the real plans in the parent's area, and the free state Health Insurance Assistance Program (SHIP) counselors answer questions without selling anything. A paid agent can also be helpful, but ask directly how they are compensated, and never let anyone rush an enrollment: legitimate choices do not need same-day decisions. If a caller demands one, it is a scam: see Impersonation scams.

The one-page comparison

Print this and use it during the call with the agent or SHIP counselor:

Medigap vs. Medicare Advantage Medigap: - Works with Original Medicare; pays the gaps - Any doctor who takes Medicare - Higher monthly premium, predictable costs - Best protection for a serious-illness year - Buy in the guaranteed-issue window Advantage: - Replaces Medicare with a private plan - Network of doctors; extra benefits (dental/vision) - Lower premium, per-visit costs, out-of-pocket max - Fits healthy, local, low-travel parents Questions: doctors? drugs? travel? worst month? window?

Related

Sources

Found an error? Report it.

What to read next