Medicare is genuinely complicated, not because it has to be, but because nobody sits you down and explains it plainly. This guide does that. Start at the top or jump to whatever you need.
Medicare is the federal health insurance program administered by the Centers for Medicare and Medicaid Services (CMS). It exists to provide healthcare coverage to people who would otherwise have trouble affording it on the private market.
Who qualifies for Medicare?
You are generally eligible if you are a U.S. citizen or permanent legal resident who has lived in the country for at least five years, and you meet one of the following:
A few things Medicare is not:
Medicare is not a single plan. It is a system built from parts that you piece together. Understanding those parts is the foundation of every decision you'll make.
Medicare is structured around four distinct parts. Parts A and B together are called "Original Medicare." Parts C and D are add-ons or replacements that expand what Original Medicare covers.
Covers inpatient hospital stays, skilled nursing facility care after a hospital stay, hospice care, and some home health services. Runs in "benefit periods" that reset after you've been out of a hospital or SNF for 60 consecutive days.
$0 premium for most enrolleesIf you (or your spouse) paid Medicare taxes for at least 40 quarters, Part A is free. Otherwise the premium is $278 to $505/month in 2025.
Covers outpatient care: doctor visits, preventive screenings, lab work, imaging, durable medical equipment (wheelchairs, CPAP machines), mental health services, and some home health care. After you meet the annual deductible, Medicare pays 80% and you pay 20%.
~$185/month in 2025Higher earners pay more through IRMAA adjustments. Annual deductible: $257 in 2025.
A private plan that replaces Parts A and B. Offered by insurers approved by Medicare. Must cover everything Original Medicare covers, and most plans include Part D drug coverage. Often adds dental, vision, hearing, and other extras. Uses networks.
$0 premium on many plansYou still pay the Part B premium ($185/month) in addition to any plan premium.
Standalone drug coverage added to Original Medicare or Medigap. Sold by private insurers. Covers a formulary of prescription medications at tiered cost-sharing. The specific drugs covered, and what you pay, varies enormously by plan and by zip code.
From ~$12/monthEnrolling late incurs a permanent penalty of ~1% of the national base premium per month you delayed.
How they fit together: Most people start with Parts A and B (Original Medicare), then either add a Medigap plan + Part D, or switch to a Part C (Medicare Advantage) plan which bundles A, B, and usually D. You cannot have both Medigap and Medicare Advantage at the same time.
This is the single biggest decision most Medicare enrollees face. There is no universally right answer, it depends on your health, your budget, your doctors, and how much predictability you want in your costs.
| Feature | Original Medicare (A + B) | Medicare Advantage (Part C) |
|---|---|---|
| Monthly premium | ~$185/month (Part B only) | $0 to $100+/month on top of Part B |
| Provider choice | Any doctor or hospital that accepts Medicare, nationwide | In-network required (HMO) or preferred (PPO). Out-of-network costs more or may not be covered. |
| Referrals | ✓ No referrals needed for specialists | Required in HMO plans. Not required in PPO plans. |
| Annual out-of-pocket cap | ✗ No cap, 20% coinsurance continues indefinitely | ✓ Capped at $3,000 to $8,500/year (federally required) |
| Prescription drug coverage | Not included, add standalone Part D separately | Usually bundled in at no extra premium |
| Dental, vision, hearing | ✗ Not covered under Original Medicare | ✓ Often included, quality varies by plan |
| Travel coverage | Covered anywhere in the U.S. Limited foreign travel with Medigap. | Usually limited to service area. Emergency coverage applies nationwide. |
| Prior authorization | Rarely required | Common for specialist visits, procedures, and some medications |
| Best for | People with complex health needs, specific specialists, or who travel frequently | People who want low monthly costs, bundled extras, and are comfortable with a network |
The 20% problem with Original Medicare: Without supplemental coverage, you pay 20% of every Medicare-approved outpatient service with no cap. A $100,000 cancer treatment leaves you with a $20,000 bill. This is why most people either add a Medigap plan or switch to Medicare Advantage, which has an out-of-pocket maximum.
Medigap plans are sold by private insurance companies to cover the gaps that Original Medicare leaves, primarily the 20% coinsurance and hospital deductibles. The benefits are standardized by federal law, meaning a Plan G from Humana covers exactly the same things as a Plan G from Aetna. The only difference is the premium.
| Benefit covered | A | B | D | F * | G | K | L | M | N |
|---|---|---|---|---|---|---|---|---|---|
| Part A coinsurance + hospital costs (up to 365 extra days) | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Part B coinsurance or copayment | ✓ | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓** |
| Blood (first 3 pints) | ✓ | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Part A hospice coinsurance | ✓ | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Skilled nursing facility coinsurance | , | ✓ | ✓ | ✓ | ✓ | 50% | 75% | ✓ | ✓ |
| Part A deductible ($1,676 in 2025) | , | ✓ | ✓ | ✓ | ✓ | 50% | 75% | 50% | ✓ |
| Part B deductible ($257 in 2025) | , | , | , | ✓ | , | , | , | , | , |
| Part B excess charges | , | , | , | ✓ | ✓ | , | , | , | , |
| Foreign travel emergency (80%) | , | , | ✓ | ✓ | ✓ | , | , | ✓ | ✓ |
| Typical monthly premium | $60 to $100 | $80 to $130 | $90 to $150 | $130 to $230 | $100 to $175 | $50 to $90 | $70 to $120 | $85 to $145 | $80 to $140 |
* Plan F is only available to those who were eligible for Medicare before January 1, 2020. ** Plan N requires up to a $20 office visit copay and up to $50 ER copay. Premiums vary by age, location, and carrier. Medigap does not cover prescription drugs, you need a separate Part D plan.
Plan G is the most popular Medigap plan for people newly eligible today. It covers everything except the Part B deductible ($257/year), meaning once you pay that once a year, your share of Medicare-approved costs is essentially zero. You can see any doctor or hospital that accepts Medicare, anywhere in the country, without referrals or network restrictions.
Plan N is the best-value option for people who want maximum flexibility at a lower monthly premium. It covers everything Plan G does except you pay up to $20 for office visits and up to $50 for ER visits that don't result in an inpatient admission. For people who don't see doctors frequently, the premium savings typically outweigh the copays.
Beyond covering what Original Medicare covers, Advantage plans often bundle in additional benefits not available under Original Medicare or Medigap. These vary widely by plan and location, they're not guaranteed, and not all plans offer all of them. Always verify what a specific plan includes before enrolling.
Ranges from cleanings and x-rays to fillings, extractions, and crowns. Most plans set an annual maximum benefit ($1,000 to $3,000). Check exactly what's covered, "dental included" can mean very different things plan to plan.
Coverage depth varies enormouslyUsually includes annual eye exams and an allowance toward glasses frames and lenses or contact lenses, typically $150 to $300/year. Some plans also cover cataract surgery lenses.
Allowance applies to in-network providersAnnual hearing exams and an allowance toward hearing aids, which Medicare otherwise doesn't cover at all. Allowances range from $500 to $2,500 per aid. Some plans work with specific hearing aid networks.
Hearing aids average $2,000 to $5,000 without coverageMany plans include SilverSneakers, Silver&Fit, or Renew Active memberships, giving you access to thousands of gyms and fitness centers nationwide at no additional cost. A significant benefit for active enrollees.
SilverSneakers covers 16,000+ locationsA quarterly or monthly credit, typically $25 to $150, loaded onto a benefits card you can use at participating pharmacies and retailers for over-the-counter health items: pain relievers, vitamins, bandages, and more.
Use-it-or-lose-it per period on most plansSome plans provide a set number of one-way trips per year to medical appointments, pharmacies, or fitness centers. Particularly valuable for enrollees who don't drive or live in areas with limited public transit.
Usually 12 to 36 one-way trips per yearVirtual visits with doctors, therapists, and specialists, often at $0 copay under Medicare Advantage. Useful for routine care, prescription renewals, and follow-ups without leaving home.
Usually $0 copay for in-network telehealthAfter certain hospital stays or procedures, some plans provide a set number of home-delivered meals (typically 14 to 28 meals) to aid recovery. A valuable benefit for enrollees who live alone or have limited mobility after hospitalization.
Activated by qualifying hospital or procedureImportant: These extras are why many people find Medicare Advantage appealing, especially at $0 premium. But the value only holds if the plan's network includes your doctors, its formulary covers your medications at reasonable cost, and its out-of-pocket maximum is manageable. A plan with great dental benefits that doesn't cover your cardiologist isn't actually a good deal.
Some Medicare Advantage plans offer to pay back a portion, sometimes all, of your monthly Part B premium. In 2025 the standard Part B premium is $185/month. A plan with a $100 giveback effectively costs you $85/month for that coverage instead of $185.
The giveback shows up one of two ways. If you receive Social Security, your Medicare deduction from your SS check is simply reduced by the giveback amount. If you're not yet on Social Security and Medicare bills you directly, you receive a lower invoice.
How plans afford it: Medicare pays Advantage plans a fixed monthly capitation rate per enrollee. Plans that offer givebacks are using a portion of that capitation payment to subsidize your Part B premium. The plan absorbs the cost, usually by having a narrower network, higher specialist copays, or less generous drug coverage elsewhere. Always compare the full picture, not just the giveback.
What to watch for: Giveback amounts change at annual enrollment. A plan offering $135/month back in 2025 might reduce that to $60 in 2026, and if you're locked into the plan, you won't notice until your SS check changes. Review your plan every year during the Annual Enrollment Period (Oct 15 to Dec 7) to make sure the giveback still makes sense relative to what you're giving up.
Ranges from a few dollars to the full $185/month. Varies by plan and by county, the same insurer may offer different givebacks in neighboring zip codes.
You must be enrolled in both Medicare Parts A and B, live in the plan's service area, and the plan must offer the giveback benefit in your specific county.
A large giveback is a signal to look closely at the rest of the plan. Compare network breadth, specialist copays, drug formulary, and out-of-pocket maximum before deciding the giveback makes it worth it.
Part D is where the details matter most. Unlike Medigap, where every plan letter has standardized benefits, Part D plans have widely different formularies, tier structures, and costs. The right plan for you depends entirely on what medications you take.
Part D plans organize covered drugs into tiers. Lower tiers cost less. Where your specific medication lands depends on the plan's formulary, and it varies between plans for the same drug.
FDA-approved generics that are chemically identical to brand-name drugs. Lowest cost-sharing, often $0 to $5 per fill.
Lowest costGeneric drugs not on the preferred list. Still affordable, typically $5 to $15 per fill depending on the plan.
Low costBrand-name medications on the plan's preferred list. Moderate cost-sharing, typically $30 to $50 per fill.
Moderate costNon-preferred brands and specialty drugs (biologics, cancer treatments). Can run $60 to $150+ per fill, or a percentage of cost for specialty.
Highest costYou pay the full cost of your drugs until you meet the annual deductible (up to $590 in 2025). Many plans waive this for generic drugs. Once you hit the deductible, you move to standard coverage.
You pay your plan's copays or coinsurance for covered drugs. This continues until your total drug costs (what you and the plan paid together) reach $2,000 in 2025, at which point you enter catastrophic coverage.
Starting in 2025, once you've spent $2,000 out of pocket on Part D drugs, you pay nothing for the rest of the year. This is a significant change from prior years, the old "donut hole" effectively no longer exists.
The late enrollment penalty is permanent and painful. If you don't sign up for Part D when you first become eligible and you don't have other creditable drug coverage, you'll pay a permanent penalty of about 1% of the national base premium per month you went without coverage. On a $35/month plan, that's an extra $3.50/month forever for every year you waited. Enroll even if you take no medications.
These two programs are constantly confused because their names are so similar. They are separate programs with different eligibility rules, run by different levels of government, and covering different things. Medicare is primarily age-based; Medicaid eligibility is based on income, assets, or disability, meaning people under 65 who qualify due to a disability may be eligible for Medicaid regardless of age.
Extra Help (Low Income Subsidy): If your income and assets are below certain thresholds, you may qualify for Extra Help, a federal program that significantly reduces Part D costs. It can lower your drug plan premium, deductible, and copays. In 2025, people with income up to 150% of the federal poverty level may qualify. I can help you determine eligibility.
Dual-eligible Special Needs Plans (D-SNPs): If you qualify for both Medicare and Medicaid, a D-SNP can coordinate benefits between both programs in one plan. These plans typically include enhanced benefits and often have $0 premiums for people who qualify. They require you to be enrolled in both Medicare and your state's Medicaid program.
Medicare enrollment is not open all the time. There are specific windows when you can sign up, switch plans, or make changes. Missing them, without a qualifying exception, can mean waiting a full year and paying penalties.
Your first opportunity to enroll in Medicare. A 7-month window that starts 3 months before the month you turn 65, includes your birthday month, and runs 3 months after. Enrolling in the first 3 months means coverage starts the month you turn 65. Waiting until after your birthday month delays coverage by 1 to 3 months.
Most important window, don't miss itIf you missed your Initial Enrollment Period and don't have a qualifying special enrollment period, you can sign up for Parts A and B during this window. Coverage starts July 1. You may also face a late enrollment penalty on Part B, 10% of the premium for each full 12-month period you delayed without creditable coverage.
Late penalty likely appliesThe main window to change Medicare coverage for the following year. You can switch from Original Medicare to a Medicare Advantage plan, switch between Advantage plans, switch between Part D drug plans, or return to Original Medicare. Changes take effect January 1. This is the window to review your plan every year, formularies, premiums, and networks change annually.
Changes take effect January 1If you're already in a Medicare Advantage plan, you can switch to a different Advantage plan or return to Original Medicare (with the option to add Part D) once during this period. You cannot use this window to switch from Original Medicare to Advantage, only AEP allows that.
One switch allowed per yearCertain life events open a special enrollment period outside the standard windows. Common qualifying events include: losing employer or union health coverage, moving out of a plan's service area, the plan terminating in your area, qualifying for Medicaid or Extra Help, and moving into or out of a skilled nursing facility. Most SEPs last 2 to 3 months from the triggering event.
Duration varies by event typeMedigap has different rules. During your Medigap Open Enrollment Period, the 6 months starting the month you turn 65 and enroll in Part B, insurers cannot deny you coverage or charge you more due to health conditions. Once that window closes, insurers in most states can medically underwrite you, which means pre-existing conditions can lead to higher premiums or outright denial.
These are the standard 2025 figures. Higher-income enrollees pay more through IRMAA surcharges on Parts B and D. Numbers change each year, check medicare.gov for the most current amounts.
IRMAA, Income-Related Monthly Adjustment Amount: If your modified adjusted gross income from two years ago was above $106,000 (single) or $212,000 (married filing jointly), you pay a surcharge on top of the standard Part B and Part D premiums. IRMAA brackets are adjusted annually. If you recently retired or had a life-changing event that reduced your income, you can appeal the surcharge.
Medicare comes with its own vocabulary. Here are the terms you'll encounter most frequently and what they actually mean.
Each guide covers one Medicare topic in full detail, the tradeoffs, the numbers, and what to actually do, without the fluff.
Put what you've learned to use. Enter your zip code on Sunfire to see every plan available in your area, with real premiums, coverage details, and Summary of Benefits documents.
These tools may not show every plan available in your area. For a complete comparison, a call with Bryce is the most reliable path.
Medicare has more exceptions, edge cases, and traps than any guide can fully cover. If anything here raised a question specific to your situation, book a free call. I'll work through it with you.