01 · Build your foundation
The letters, in plain English.
Medicare is federal health insurance generally available at age 65, with earlier eligibility in certain disability, ALS, or end-stage renal disease situations. Your eligibility and start dates matter more than the amount of mail arriving at your home.
Part A · Hospital
Helps cover inpatient hospital care, qualifying skilled nursing facility care, hospice, and some home health care. It is not blanket coverage for long-term custodial care.
Part B · Medical
Helps cover doctor visits, outpatient services, medical equipment, and preventive services. Parts A and B together are called Original Medicare.
Part C · Medicare Advantage
A private Medicare-approved plan that provides your Part A and Part B benefits. Most include Part D. You must have both A and B and keep paying your Part B premium.
Part D · Prescription drugs
Private-plan coverage for prescription drugs. Each plan has a covered-drug list, called a formulary, plus pharmacy rules and cost sharing.
Medigap is different: Medicare Supplement Insurance helps pay certain Original Medicare costs. It is not Medicare Advantage. “Part A” and “Medigap Plan A” are different things.
Read more: Medicare’s parts · Medigap basics
02 · Compare the structure
Two main ways to receive coverage.
| Consideration | Original Medicare | Medicare Advantage |
|---|---|---|
| Building blocks | Parts A + B. You may add a separate Part D plan and Medigap or other supplemental coverage. | Private plan delivers A + B benefits; usually includes Part D. |
| Doctors | Generally any U.S. doctor or hospital that takes Medicare. | Networks, referrals, and out-of-network rules depend on the plan. |
| Approvals | Prior authorization is usually not required, with exceptions. | Prior authorization may be required for certain services. |
| Medical spending limit | No annual out-of-pocket cap by itself. Supplemental coverage can help. | Annual limit for covered Part A/B services; check network-specific limits. Premiums and Part D spending are separate. |
| Extra benefits | Routine dental, vision, and hearing generally are not included. | May include extra benefits, with limits and conditions. |
02A · Medicare Supplement plans
What do the plan letters cover?
Medicare Supplement Insurance, also called Medigap, helps pay certain costs left over after Original Medicare pays. You generally need Parts A and B, pay a separate Medigap premium, and arrange prescription coverage separately. A Medigap policy covers one person, not a couple.
The letter describes the standardized benefits, not the insurance company. The same letter offers the same standardized benefits across insurers, but premiums can differ. This chart applies to the standard lettered plans used in Utah, Idaho, and most states. Massachusetts, Minnesota, and Wisconsin use different standardization systems.
100% means the policy covers the full listed benefit, subject to its terms. A percentage means it covers that share. “No” means the policy does not cover that benefit; Medicare may still pay its own share. “N/A” means that specific annual limit does not apply. This is not a promise to pay every medical bill.
On a phone, swipe the chart sideways to compare every letter. The benefit names stay visible.
| Benefit | Plan A | Plan B | Plan C | Plan D | Plan F | Plan G | Plan K | Plan L | Plan M | Plan N |
|---|---|---|---|---|---|---|---|---|---|---|
| Part A coinsurance + up to 365 extra hospital days | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| Part B coinsurance / copayments | 100% | 100% | 100% | 100% | 100% | 100% | 50% | 75% | 100% | 100%* |
| First 3 pints of blood | 100% | 100% | 100% | 100% | 100% | 100% | 50% | 75% | 100% | 100% |
| Part A hospice coinsurance / copayments | 100% | 100% | 100% | 100% | 100% | 100% | 50% | 75% | 100% | 100% |
| Skilled nursing facility coinsurance | No | No | 100% | 100% | 100% | 100% | 50% | 75% | 100% | 100% |
| Part A deductible | No | 100% | 100% | 100% | 100% | 100% | 50% | 75% | 50% | 100% |
| Part B deductible | No | No | 100% | No | 100% | No | No | No | No | No |
| Part B excess charges | No | No | No | No | 100% | 100% | No | No | No | No |
| Foreign-travel emergency (plan limits apply) | No | No | 80% | 80% | 80% | 80% | No | No | 80% | 80% |
| 2027 annual out-of-pocket limit | N/A | N/A | N/A | N/A | N/A | N/A | Pending verification | Pending verification | N/A | N/A |
Important chart notes
- *Plan N: Part B coinsurance is covered except up to $20 for some office visits and up to $50 for an emergency-room visit that does not result in an inpatient admission. Plan N does not cover the Part B deductible or excess charges.
- Plans C and F: Not available to people newly eligible for Medicare on or after January 1, 2020. People eligible before that date may still be able to buy them. Plan C is not Medicare Part C.
- High-deductible F and G: Available in some states. You pay eligible Medicare-covered costs up to Pending verification for 2027 before the high-deductible policy pays. This is different from standard F or G; F’s eligibility restriction still applies.
- Plans K and L: After you meet the listed yearly out-of-pocket limit and the yearly Part B deductible (2027 amount pending verification), the plan pays 100% of covered services for the rest of that calendar year.
- Foreign travel: The benefit generally pays 80% of qualifying emergency care after a $250 calendar-year deductible, with a $50,000 lifetime maximum, when the emergency begins during the first 60 days of a trip. It is not comprehensive travel insurance.
- Dates matter: Dollar amounts follow your selected coverage year. Pending 2027 amounts were not confirmed in the official sources at the October 1 review. Older policies may differ. Not every insurer sells every letter, and eligibility or underwriting can limit your options.
A closer look at G and N
Standard Plan G
Covers the chart’s listed domestic cost-sharing benefits except the Part B deductible. It includes Part B excess-charge coverage and the limited foreign-travel emergency benefit. Compare its premium with the costs you expect to pay yourself.
Plan N
You pay the Part B deductible, applicable office and emergency-room copays, and any Part B excess charges. Compare those potential costs with the quoted premium difference. Ask whether your doctors accept Medicare assignment.
What are Part B excess charges?
When a provider is legally allowed to charge above Medicare’s approved amount, that difference is an excess charge. Not every provider charges it. Standard Plans F and G cover this benefit; Plan N does not.
What does Medigap generally not cover?
Medigap generally does not cover long-term custodial care, routine dental or vision care, hearing aids, or private-duty nursing. Policies sold after 2005 do not include prescription drug coverage. It does not work as a supplement to Medicare Advantage.
When should I apply?
Your federal six-month Medigap Open Enrollment Period begins when you are both 65 or older and enrolled in Part B. Outside that window or other protected rights, health questions and medical underwriting may apply. State protections can differ. Review your eligibility before dropping existing coverage.
Review enrollment timelinesSources: Medicare’s Choosing a Medigap Policy booklet, printed page 7 (PDF) · What Medigap covers · How Medigap works. Reviewed October 1, 2026.
03 · Know which clock applies
Your enrollment timelines.
First enrollment around age 65
The usual Initial Enrollment Period is seven months: three months before your 65th-birthday month, that month, and three months after. A birthday on the first day of a month shifts the usual eligibility timeline one month earlier. Confirm your dates with Social Security.
- 3 months
before - 2 months
before - 1 month
before - Birthday
month - 1 month
after - 2 months
after - 3 months
after
Example: If you turn 65 on June 18, your usual window is March 1 through September 30. Enroll in Part B during March–May for a June 1 start. Enroll in June for a July 1 start; enrolling during July–September generally starts Part B the following month. This example assumes age-based eligibility and no special circumstances.
Enrollment and coverage start dates
| Window | Who / what it is for | Timing |
|---|---|---|
| Annual Enrollment | Change Medicare Advantage or Part D coverage, or switch between Original Medicare and Medicare Advantage. | October 15–December 7. Changes generally start January 1. |
| Medicare Advantage Open Enrollment | For people already in Medicare Advantage: one switch to another Advantage plan, or return to Original Medicare and optionally join Part D. Not a general chance to enter Advantage from Original Medicare. | January 1–March 31. Generally effective the following month. |
| General Enrollment | Enroll in Part B or premium-Part A if you missed your initial window and do not qualify for a special period. Penalties may apply. | January 1–March 31. Coverage generally starts the following month. |
| Special Enrollment | Certain events, such as a move or loss of qualifying coverage. Part B and private-plan rules are different. | Event-specific deadlines. Check before your coverage ends. |
| Medigap Open Enrollment | Federal opportunity to buy available Medigap coverage without health-based denial or pricing. | Six months starting the first month you are both 65 or older and enrolled in Part B. Not an annual fall event. |
Outside protected Medigap enrollment or guaranteed-issue rights, medical underwriting may apply. State rules can add protections; do not assume switching back from Medicare Advantage guarantees access to Medigap.
Plan enrollment windows · General Enrollment · Medigap timing and protections
04 · Coordinate existing coverage
Still working? Check before delaying.
Group coverage through your or your spouse’s current employment may let you delay Part B without a penalty. Employer size and which insurance pays first still matter. Ask your benefits administrator before making a change.
- Part B: The employment-based special window generally lasts eight months after employment or qualifying coverage ends, whichever happens first. Coordinate enrollment before coverage ends to avoid a gap.
- COBRA and retiree coverage: These do not extend the Part B employment-based deadline.
- Drug coverage: Ask for written confirmation that coverage is “creditable,” meaning expected to pay at least as much as Medicare drug coverage. Part D deadlines are separate.
- HSA contributions: Medicare enrollment can make contributions ineligible. Premium-free Part A can be retroactive up to six months when enrolling after 65, but not before eligibility. Discuss the stopping date with your benefits administrator or tax professional before applying.
05 · Look beyond the premium
What will I pay?
A premium is what you pay to maintain coverage. A deductible is an amount you pay before certain benefits begin. A copay is a fixed charge; coinsurance is a percentage of an allowed cost.
Use the year-specific Medicare reference panel above for Part A, Part B, and Part D amounts. Plan-specific premiums and benefits vary. Figures marked pending are not estimates.
What about late-enrollment penalties?
Part B’s penalty is generally 10% for each full 12-month delay without an applicable exception and usually lasts as long as you have Part B. Part D can impose a penalty after 63 consecutive days without Part D or other creditable drug coverage after your initial window. The Part D calculation generally uses 1% of the national base beneficiary premium for each full uncovered month. Confirm exceptions and your own dates before delaying.
Can I get help paying?
Medicare Savings Programs may help with Medicare premiums and, depending on the program, other costs. Extra Help assists with Part D costs. Medicaid may provide additional support. Eligibility varies; ask for a benefits screening rather than assuming you earn too much.
06 · Your research worksheet
Before you choose a plan.
Use these checkboxes as a reading aid. They stay on this page only and are not submitted or saved.
Which documents should I read?
Start with the Summary of Benefits for the overview, then the Evidence of Coverage for detailed plan rules. Use the provider directory and formulary for access and prescriptions. Existing members should read the Annual Notice of Change to understand next year’s differences. Confirm important details directly with the plan and providers.
07 · From application to coverage
What to expect next.
- Confirm how you enroll in A and B. Some people are enrolled automatically; others apply through Social Security. Check your situation instead of assuming a card will arrive.
- Check your Medicare card. Confirm your name and Part A/B dates. Keep your Medicare number private.
- Choose additional coverage if appropriate. Applying for A and B does not automatically enroll you in a private Advantage, Part D, or Medigap plan.
- Wait for confirmation. Save application records, verify the effective date, and watch for plan cards and materials. Coordinate with current coverage before ending it.
- Prepare for the first visit or refill. Check which card to use, payment arrangements, and any transition questions with your plan.
- Review each year. Recheck providers, prescriptions, costs, and changes to your needs before deciding whether to keep or change coverage.
08 · Clear up common mix-ups
Questions worth asking.
Does fall enrollment mean I can wait to sign up for Part B?
No. The October–December plan window is different from your Part A/B enrollment opportunity. Start with your own eligibility and current coverage.
Can I combine Medigap and Medicare Advantage?
Medigap is designed to supplement Original Medicare. It cannot pay Medicare Advantage copays or deductibles. Compare these as different coverage paths.
Is Medigap Plan G the same as Medicare Part G?
No. There is no Medicare Part G. Plan G is one of the standardized Medicare Supplement plan designs.
Can I research without enrolling or booking a meeting?
Absolutely. Read this guide, follow the official sources, and write down your questions. When you are ready, you can explore Kyle’s online shopping link or request a conversation.
Keep reading
Go straight to the source.
The links throughout this guide lead to Medicare.gov. For independent counseling, you can also contact your State Health Insurance Assistance Program (SHIP). Medicare’s phone line is 1-800-MEDICARE (1-800-633-4227).
Reviewed October 1, 2026. This guide explains common situations; state protections, special enrollment rights, and individual circumstances can differ. Follow current official guidance and the actual plan documents.
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