The single most consequential Medicare decision most seniors face: Original Medicare with a Medigap supplement, or Medicare Advantage? Millions choose Advantage every year based on the low or $0 premium — and then discover unexpected costs when they actually need care.
This guide cuts through the marketing to show you what each option actually costs — in real scenarios, with real numbers.
Medicare Advantage often costs less for healthy people who rarely use healthcare. Original Medicare + Medigap often costs less — and offers far more flexibility — for people with complex health needs, frequent specialist visits, or those who travel. The "right" answer depends entirely on your individual situation.
What Each Option Actually Is
Original Medicare (Parts A + B) is the federal government's direct insurance program. You can see any doctor or hospital in the US that accepts Medicare — and that's over 93% of all physicians. There are no network restrictions, no referrals needed for specialists, and no prior authorization for most services.
Medicare Advantage (Part C) replaces Original Medicare with a private insurance plan. The insurer receives a fixed payment from the government to cover your care and adds benefits like dental and vision. Most plans work as HMOs (you need referrals and must use network providers) or PPOs (network preferred but out-of-network allowed at higher cost).
Real Cost Comparison: Three Scenarios
Scenario 1: Healthy Senior, Minimal Care
Original Medicare + Plan G Medigap: ~$174.70 (Part B) + ~$145 (Plan G premium) = $320/month = $3,840/year. Out of pocket: $257 (Part B deductible). Total: ~$4,100/year.
Medicare Advantage (typical $0 premium): $174.70 (Part B only) = $2,096/year. Out of pocket: minimal if you stay in network. Total: ~$2,200/year.
Winner for healthy seniors: Medicare Advantage — saves roughly $1,900/year if you use little healthcare.
Scenario 2: Moderate Healthcare User
Original Medicare + Plan G: $4,100/year fixed. Out-of-pocket after deductible: $0 for all covered services. Total: $4,100/year.
Medicare Advantage: $2,096 premiums + copays ($25–$50/specialist visit × 12 visits = $480) + cost-sharing for labs/imaging ($200) = ~$2,800/year. Total: ~$2,800/year.
Winner: Medicare Advantage still slightly ahead — but the gap is closing.
Scenario 3: Serious Illness or Major Surgery
Original Medicare + Plan G: $4,100/year. Out of pocket after deductible: $0 regardless of how much care you need. Total: $4,100/year — no surprises.
Medicare Advantage: $2,096 premiums + cost-sharing for hospitalization ($300–$400/day for days 1–6 = $2,400) + specialist copays + prior authorization delays + potential out-of-network costs if you need a specialist not in network. Out-of-pocket maximum: $8,850 (in-network) in 2026. Worst case total: $10,946/year.
Winner: Original Medicare + Medigap by a large margin for serious illness.
The Hidden Costs of Medicare Advantage
Advantage plans are marketed aggressively because insurers make significant profit margins on them. Here are the costs that don't appear in the premium:
- Prior authorization: MA plans require pre-approval for many services — specialists, surgeries, imaging. Denials are common and delays can be medically harmful. Original Medicare requires prior auth for almost nothing.
- Network restrictions: Your favorite doctor may not be in network. Cancer centers like Mayo Clinic and MD Anderson often don't accept MA plans.
- High out-of-pocket maximum: MA plans can expose you to up to $8,850 in-network costs in a bad health year.
- Plan instability: MA plans can change their formularies, networks, and benefits every single year. Your $0 premium plan this year may cost $80/month next year.
Who Should Choose Each Option
Original Medicare + Medigap is better if you: have complex health conditions, see multiple specialists, want the freedom to use any doctor anywhere in the US, travel frequently, live part-year in another state, or value predictable costs above all else.
Medicare Advantage may be better if you: are relatively healthy, have a regular primary care doctor in the plan network, appreciate extra benefits (dental, vision, gym), live in one location year-round, and are comfortable with managed care.
You can switch from Medicare Advantage back to Original Medicare during Annual Enrollment (Oct 15–Dec 7). However, in most states, Medigap insurers can deny you coverage or charge higher rates based on health conditions once you're past your initial enrollment period. This is why many experts recommend thinking carefully about Medigap when you first turn 65, rather than starting with Advantage and trying to switch later.
Frequently Asked Questions
Is Medicare Advantage better than Original Medicare?
It depends on your health needs. Medicare Advantage often costs less for healthy seniors who rarely need care. Original Medicare plus a Medigap plan typically provides better protection for seniors with complex health conditions, multiple specialists, or those who travel frequently.
What are the hidden costs of Medicare Advantage?
Medicare Advantage hidden costs include prior authorization requirements that can delay or deny care, narrow provider networks that exclude your preferred doctors, out-of-pocket maximums up to $8,850 in-network, and plan instability — benefits, networks, and premiums can change every January.
Can I switch from Medicare Advantage to Original Medicare?
Yes — you can switch during the Annual Enrollment Period (October 15–December 7) or the Medicare Advantage Open Enrollment Period (January 1–March 31). However, in most states, Medigap insurers can deny coverage or charge higher premiums based on health conditions if you switch after your initial enrollment period.
Does Medicare Advantage cover out-of-state care?
HMO-based Medicare Advantage plans generally do not cover out-of-state care except in emergencies. PPO plans cover out-of-network care but at higher cost-sharing. Original Medicare covers any Medicare-accepting provider anywhere in the US — making it the better choice for frequent travelers.
What is the out-of-pocket maximum for Medicare Advantage in 2026?
In 2026, Medicare Advantage plans must cap in-network out-of-pocket costs at $8,850 per year. Some plans set lower caps. Combined in- and out-of-network maximums can be higher. Original Medicare with Plan G Medigap has no out-of-pocket maximum beyond the $257 Part B deductible.