Medicare Advantage vs Original Medicare: How to Actually Choose Before Dec 7
Open enrollment runs October 15-December 7, 2026 for 2027 coverage. Here's how Medicare Advantage and Original Medicare actually compare on cost, networks, and drug coverage.
Medicare's Annual Enrollment Period for 2027 coverage runs October 15 to December 7, 2026, with changes taking effect January 1, 2027. During it you can switch between Original Medicare and Medicare Advantage, or change Part D drug coverage. A separate Medicare Advantage-only period runs January 1-March 31, 2027.
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About the Author
Sujit KarkiFinance Researcher & Market Analyst
Independent finance researcher and market analyst with expertise in macroeconomics, equity markets, and personal finance. I help regular investors make better-informed decisions through rigorous, data-driven analysis.
Open enrollment for 2027 coverage runs October 15-December 7, 2026.
Medicare Advantage typically costs less upfront but limits you to a network and often needs prior authorization.
Original Medicare plus Medigap costs more monthly but gives you provider flexibility nationwide.
The 2027 Part B premium is still a projection (~$209.50/month) — CMS confirms the final number around November 2026.
Every fall the same question lands in my inbox: should I switch to Medicare Advantage, or stay with Original Medicare? It's not a question with one right answer — it genuinely depends on how much you travel, how many specialists you see, and how much monthly premium versus potential out-of-pocket risk you're willing to carry. Let me walk through how to actually decide before the December 7 deadline, not just what the ads say.
The two paths, honestly compared
Feature
Original Medicare + Medigap
Medicare Advantage
Monthly premium
Higher — Part B plus a separate Medigap premium
Often $0-low, on top of Part B
Provider network
Any doctor nationwide who accepts Medicare
Restricted to plan's network, usually regional
Prior authorization
Rarely required
Common for many services
Drug coverage
Separate Part D plan needed
Usually bundled in
Dental/vision/hearing
Not included
Often included as an extra
Out-of-pocket cap
No hard cap without Medigap
Annual out-of-pocket maximum required by law
Neither column is universally "better." Original Medicare plus Medigap is the more expensive monthly commitment that buys you the most flexibility — genuinely useful if you split time between states, see a lot of specialists, or simply want the fewest network restrictions on which doctor you can see. Medicare Advantage is the lower-premium, more managed-care option — a reasonable trade for people in good health who are comfortable with a defined network and don't mind prior authorization on some services.
The dates that actually matter
The Annual Enrollment Period (AEP) for 2027 coverage runs October 15 to December 7, 2026, with any changes you make taking effect January 1, 2027. This is the main window where you can switch between Original Medicare and Medicare Advantage, or change your Part D drug plan.
There's a second, narrower window worth knowing: the Medicare Advantage Open Enrollment Period runs January 1 to March 31, 2027, but it only applies if you're already enrolled in an MA plan — it lets you make one additional switch (to a different MA plan, or back to Original Medicare) if your fall choice isn't working out. It is not a second chance to newly enroll from Original Medicare into MA outside the fall window.
Read your ANOC first
Every Medicare Advantage and Part D plan sends an Annual Notice of Change (ANOC) by September 30, and full plan details for the upcoming year post on medicare.gov starting October 1 — two weeks before you can actually enroll. This document is the single most useful thing you'll get in the mail all year and the one most people skip. It tells you exactly what's changing in your plan for next year: premium, network, formulary, and cost-sharing changes specific to your coverage, not generic marketing.
Warning
Plans change their drug formularies and networks every year, sometimes significantly. A plan that was the right fit last year can quietly become a worse fit for January without you doing anything — the ANOC is how you catch that before it costs you.
Networks, prior auth, and Medigap
The two costs people underweight on Medicare Advantage are network risk and prior authorization friction. If you see an out-of-network provider on many MA plans, you can face significantly higher costs or no coverage at all outside of emergencies. Prior authorization requirements — where the plan must approve certain services before you get them — have become more common on Medicare Advantage plans and can delay care in ways Original Medicare rarely does.
On the Original Medicare side, the biggest thing to plan around is that a Medigap policy is medically underwritten if you apply outside your initial enrollment window in most states — meaning if you drop Medigap for an MA plan now and want to switch back to Original Medicare later, you may not be guaranteed the ability to buy a Medigap policy at standard rates, depending on your state's specific protections. That asymmetry — easy to leave Original Medicare, sometimes hard to fully return — is worth weighing before switching for a lower premium alone.
Compare total cost, not premium
How I calculated this: the estimator sums the actual cost buckets Medicare.gov's own Plan Finder breaks out for any plan — monthly premium × 12, plus a realistic annual out-of-pocket estimate scaled to your self-reported care level (light, moderate, heavy), capped at the plan's published maximum out-of-pocket. It's not a substitute for running your own ZIP code and specific plans through Medicare's Plan Finder, but it makes the premium-vs-total-cost gap visible before you do that deeper comparison.
Interactive · compare estimated 2027 total cost
Medicare Advantage vs. Original Medicare + Medigap
Medicare Advantage monthly premium$0
Medigap monthly premium$150
Medicare Advantage annual OOP maximum$8,000
Medicare Advantage, est. annual
$0
Original + Medigap, est. annual
$0
Includes a projected 2027 Part B premium of $210/month (2026 Medicare Trustees Report) — CMS has not yet confirmed the final figure as of this writing. Estimate only, not insurance advice; compare real plans at medicare.gov/plan-compare.
Medicare total cost comparison — data table
Projected 2027 Part B (shared base cost)
$2,514/yr
Medicare Advantage est. annual total
$6,014
Original + Medigap est. annual total
$5,514
The premium is the number in the ad. The number that actually determines whether you come out ahead is your total annual cost — premium plus realistic out-of-pocket spending for your actual health needs. A $0-premium Medicare Advantage plan with a $7,500 out-of-pocket maximum can cost more in a heavy-care year than a higher-premium Medigap plan that covers nearly everything. For the underlying Part B premium both paths share, I've also written about the projected 2027 Part B premium and what's still unconfirmed — worth reading alongside this if you want the full year-end Medicare picture, including how a qualified charitable distribution can help manage the income that determines your IRMAA surcharge, which I cover in a separate piece on QCDs.
Here's What I'd Actually Do
Read your ANOC the day it arrives, not in November. It tells you exactly what's changing before you have to make a decision.
List every doctor and prescription you actually use, then check each against a plan's specific network and formulary — not just its star rating.
Estimate a "heavy care year" scenario, not just this year's typical spending, before assuming a low-premium MA plan is the cheaper option overall.
Understand your state's Medigap underwriting rules before dropping Original Medicare + Medigap for an MA plan you might want to leave later.
Use medicare.gov/plan-compare directly rather than relying solely on a single insurance agent's recommendation — it's free, unbiased, and shows every plan available in your area.
Frequently Asked Questions
Medicare's Annual Enrollment Period for 2027 coverage runs October 15 to December 7, 2026, with changes taking effect January 1, 2027. During it you can switch between Original Medicare and Medicare Advantage, or change Part D drug coverage. A separate Medicare Advantage-only period runs January 1-March 31, 2027.
This is educational content, not insurance or financial advice. Plan details, networks, and premiums change every year and vary by state and zip code. Compare current plans at medicare.gov or talk to a licensed Medicare counselor (SHIP) before enrolling. See the full disclaimer.
Sujit Karki|||5 min read