This article covers the major Medicare options, the differences between Original Medicare and Medicare Advantage (Part C), who each option tends to fit best, and what you can expect to pay. Whether you are turning 65 soon, already enrolled, or helping a parent through the process, we hope this helps you make a confident decision.
The Building Blocks of Medicare
Medicare is made up of five parts, and understanding them makes everything else easier:
Part A (Hospital)
Part B (Medical)
Part C (Medicare Advantage)
Part D (Prescription Drugs)
Medigap (added to Parts A and B)
There are really two paths. Path one is Original Medicare (Parts A and B), typically paired with a stand-alone Part D drug plan and a Medicare Supplement (“Medigap”) policy to fill the gaps. Path two is Medicare Advantage (Part C), where a private insurer bundles your hospital, medical, and usually drug coverage into one plan. You still pay your Part B premium either way. The Congressional Budget Office projects Medicare Advantage will cover about 63% of beneficiaries by 2034.
Original Medicare: Freedom and Predictability
Original Medicare is administered by the federal government. Its biggest selling point is access: you can see any doctor or hospital in the country that accepts Medicare, with no network restrictions and generally no referrals or prior authorizations for specialists.
The catch is that Original Medicare alone has real gaps. After the Part B deductible, you generally pay 20% of approved costs, with no annual out-of-pocket limit. That uncapped 20% is why most people on Original Medicare add a Medigap policy which increases premium costs when compared with a Part C plan. There are 8 standardized Medigap plans currently available to new enrollees, labeled by letter: A, B, D, G, K, L, M, and N. Plan G is the most popular Medigap policy choice for new enrollees today; after you pay the Part B deductible, it covers essentially all remaining Medicare-approved costs.
A critical note on Medigap: Your one-time, six-month Medigap Open Enrollment window begins once you are 65 and enrolled in Part B. During it, insurers cannot deny you or charge more based on your health; afterward, most applications face medical underwriting. In California, the “birthday rule” also lets current Medigap members switch to an equal or lesser plan without underwriting within 60 days of the start of their birthday month. That makes it a good yearly chance to shop your Plan G premium, but it does not help anyone returning from Medicare Advantage.
Medicare Advantage (Part C): Convenience and Low Premiums
Medicare Advantage plans are offered by private insurers that contract with Medicare. They must cover everything Original Medicare does, and many add dental, vision, hearing, or gym benefits. Low cost is the big draw: in 2026, 75% of enrollees in individual plans with drug coverage pay nothing beyond their Part B premium.
The tradeoffs are networks and plan rules. Most plans are HMOs or PPOs, and prior authorization from insurance required for care is common. On average, enrollees can see about half the physicians available under traditional Medicare in their area. Always confirm your doctors and preferred hospital are in-network for the coming year.
Which Option Fits Which Person?
There is no universally “right” answer, but these are the patterns we see most often with clients.
Original Medicare with Medigap tends to fit best if you:
• Travel frequently, split time between two homes, or plan to spend part of the year out of state
• Have (or anticipate) ongoing health conditions, specialist care, or a desire to access top-tier specialty centers without network hurdles
• Value predictable costs and would rather pay a higher fixed premium than face variable bills
• Are in your initial Medigap enrollment window. This is the one time you are guaranteed access regardless of health, and it may not come again.
Medicare Advantage tends to fit best if you:
• Are in good health and want to keep monthly fixed costs low
• Are comfortable with a network, and your doctors and hospital system participate in the plan
• Like the simplicity of one card and one plan, and would use bundled dental, vision, or hearing benefits
• Spend most of the year locally
Expected Cost Differences
The cost comparison comes down to fixed versus variable costs, and Medigap and Part D premiums vary by age, zip code, and carrier. Original Medicare with Medigap Plan G and a Part D plan averages about $5,500 per person per year in premiums, while a Part C plan averages roughly half that. In a difficult health year, the math flips: Part C out-of-pocket costs are capped at $9,250 in-network ($13,900 combined for PPOs) plus up to $2,100 for prescriptions, or roughly $14,000 all-in with premiums. Original Medicare with Plan G and Part D tops out around $7,900 all-in (assuming the standard Part B premium).
A note for higher-income households (IRMAA): Your Part B and Part D premiums may be higher based on your annual income from two years ago. The monthly Part B premium ranges from $202.90 to $689.90 in 2026, depending on income. This matters for tax planning. Roth conversions, large capital gains, or the sale of a business or rental property can push you into a higher IRMAA tier two years down the road. If your income dropped because of a life-changing event like retirement, you can file Form SSA-44 to request a reduction.
Mark Your Calendar: Medicare Open Enrollment
Annual Enrollment Period: October 15 – December 7, 2026. Any changes you make take effect on January 1, 2027. During this window you can switch Advantage plans, change Part D plans, or move between Original Medicare and Medicare Advantage. Keep in mind that a move back to Original Medicare does not guarantee you a Medigap policy.
Medicare Advantage Open Enrollment: January 1 – March 31, 2027. This window is only for people already enrolled in a Medicare Advantage plan and allows one additional switch or a return to Original Medicare.
Final Thoughts
Working with a Medicare broker to help determine which plan is right for you can be a great option. Brokers are licensed agents who compare plans on your behalf at no direct cost to you because the insurance companies pay them commissions. However, they generally represent a limited list of carriers – so make sure to ask which carriers they do and don’t represent, especially if you’re hoping to keep your current healthcare team. For unbiased help, you can also use Medicare.gov’s Plan Finder, call 1-800-MEDICARE, or get free one-on-one counseling through California’s HICAP program.
We are happy to review how IRMAA fits into your tax strategy and Roth conversion planning. Please give our office a call if you would like to talk through your options before the December 7 deadline.