Medicare Basics: Who Can Qualify, And When?

Medicare is a government-run health insurance program that helps cover costs for hospital care, doctor visits, prescriptions, and other important medical services. Most people think of Medicare as something for those 65 and older—but that’s only part of the picture.

Medicare also provides vital coverage for younger individuals who qualify due to a disability or certain long-term health conditions. So even if you’re under 65, you might still be eligible.

Knowing when you qualify, what Medicare includes, and how to sign up can help you or a loved one make confident healthcare choices. Whether you’re nearing retirement, assisting a family member, or managing a disability, your options and timing may look different based on your situation.

It’s a common myth that Medicare is only for retirees. But in truth, people of all ages use it—while others may rely on Medicaid or marketplace plans until they become eligible. This guide is here to help you understand how Medicare fits into your life, no matter where you are on the journey.

Understanding the Four Parts of Medicare

Whether you’re already enrolled or getting ready to sign up, knowing how Medicare works can help you make smart choices about your healthcare. Medicare is divided into four main parts, each offering different types of coverage:

Part A – Hospital Insurance
Part B – Medical Insurance
Part C – Medicare Advantage Plans (private alternatives to Original Medicare)
Part D – Prescription Drug Coverage

Let’s start with the basics of Part A, which covers hospital-related services.

Medicare Part A: Hospital Insurance

Medicare Part A helps cover care you receive as a hospital inpatient, including stays in skilled nursing facilities, hospice care, and some types of home health services. Many people qualify for this coverage without having to pay a monthly premium—depending on their work history or that of their spouse.

Do You Have to Pay for Part A?

Most people don’t have to pay for Part A if they—or their spouse—paid Medicare taxes for at least 10 years (or 40 quarters). If you haven’t met that threshold, you’ll need to pay a monthly premium:

Less than 30 quarters of work credits: $515/month
30–39 quarters of work credits: $285/month

You may qualify for premium-free Part A at age 65 if any of the following apply:

You’re already receiving retirement benefits from Social Security or the Railroad Retirement Board
You’re eligible for those benefits but haven’t filed for them yet
You or your spouse had Medicare-covered government employment
You’re currently married to someone who qualifies for premium-free benefits
You’re divorced (married at least 10 years) and your ex-spouse qualifies
You’re widowed (married at least nine months before your spouse passed) and your late spouse was eligible

People under 65 may also qualify for premium-free Part A if they:

Have received Social Security or Railroad Retirement disability benefits for at least 24 months
Have End-Stage Renal Disease (ESRD) and meet certain criteria

Other Costs with Part A

Even if you get Part A without paying a premium, there are still out-of-pocket costs for hospital stays and related care.

Hospital & Inpatient Costs (2025)

Medicare helps cover hospital stays but you’ll share some of the costs based on how long you’re admitted:

$1,676 deductible per benefit period (you pay this first)
Days 1–60: $0 coinsurance
Days 61–90: $419 per day
Days 91–150: $838 per day (using limited lifetime reserve days)
After 150 days: You pay 100% of costs

You only get 60 lifetime reserve days total—for all future hospital stays combined.

In psychiatric hospitals, Medicare caps your coverage at 190 days total during your lifetime. However, there’s no cap at general hospitals for mental health stays. You’ll also owe 20% of the cost for any doctor services you receive during inpatient mental health treatment.

Skilled Nursing Facility (SNF) Coverage

If you need recovery care in a certified Skilled Nursing Facility (SNF), Medicare may help—but only if specific conditions are met:

You must have been hospitalized for at least three consecutive days
You must enter the SNF within 30 days of your hospital discharge
Your care must be medically necessary and related to your prior hospital stay

SNF Costs (2025):

Days 1–20: $0
Days 21–100: $209.50 per day
Day 101+: You pay the full cost

Part B: Outpatient & Doctor Visit Coverage

Medicare Part B helps pay for services you receive outside of a hospital, including doctor visits, preventive care, lab tests, medical equipment, and more. Unlike Part A, everyone enrolled in Part B pays a monthly premium—and your income can affect how much you pay.

Monthly Premiums for Part B

All Medicare Part B participants must pay a premium, regardless of work history. If you already receive benefits from Social Security, the Railroad Retirement Board, or the Office of Personnel Management, your Part B premium is automatically deducted from your benefit check. Otherwise, you’ll get a bill in the mail.

Standard Part B premium for 2025: $185/month

If your income is above a certain level, you’ll pay a higher premium. This is determined by your modified adjusted gross income (MAGI)—your total annual income plus any tax-exempt interest.

Premium amounts are based on your income tax return from two years ago. Here’s what higher-income enrollees can expect to pay in 2025:

Individual Return	Joint Return	Married Filing Separately	Monthly Premium
$106,000 or less	$212,000 or less	$106,000 or less	$185
$106,001–$133,000	$212,001–$266,000	N/A	$259
$133,001–$167,000	$266,001–$334,000	N/A	$370
$167,001–$200,000	$334,001–$400,000	N/A	$480.90
$200,001–$499,999	$400,001–$749,999	$106,001–$393,999	$591.90
$500,000+	$750,000+	$394,000+	$628.90

Deductible and Coinsurance Costs

In addition to your monthly premium, you’ll need to pay an annual deductible before Medicare starts helping with costs.

2025 Part B deductible: $257/year

After you’ve met this deductible, Medicare will cover 80% of the approved cost for most services. You’re responsible for the remaining 20% coinsurance—this includes things like:

Doctor visits
Outpatient physical, speech, or occupational therapy
Durable medical equipment (DME) like walkers or oxygen equipment

Some services, like lab tests, home health care, and depression screenings, are covered in full—meaning you don’t have to pay anything out of pocket for those.

Part C: Medicare Advantage Plans

Medicare Part C—commonly known as Medicare Advantage—is an alternative to Original Medicare (Parts A and B). These plans are offered by private insurance companies and often include extra benefits like vision, dental, hearing, and even prescription drug coverage.

To enroll in a Medicare Advantage plan, you must first sign up for both Part A and Part B. Once enrolled, you’ll receive your Medicare benefits through the Advantage plan instead of directly through the federal government.

How Medicare Advantage Works

Medicare Advantage plans function much like traditional health insurance. You’ll usually need to use the plan’s network of doctors and hospitals to get the best rates, and you may have to follow certain rules about referrals or specialist visits. In return, these plans often offer lower out-of-pocket costs and more comprehensive benefits than Original Medicare alone.

There are several types of Medicare Advantage plans, each with its own structure and rules.

Types of Medicare Part C Plans

Health Maintenance Organization (HMO)
HMO plans require you to get care from providers within the plan’s network (except for emergencies). You’ll usually need a referral from your primary care doctor to see a specialist. Using out-of-network providers often means you’ll pay the full cost.
Preferred Provider Organization (PPO)
PPO plans offer more flexibility—you can see doctors outside the network, though it will cost more. Unlike HMOs, you typically don’t need a referral to visit a specialist.
Private Fee-for-Service (PFFS)
These plans let you see any Medicare-approved provider who agrees to the plan’s terms. Some PFFS plans include a provider network with lower costs, while others don’t. Not all PFFS plans cover prescription drugs, so if yours doesn’t, you can enroll in a Part D plan separately.
Special Needs Plans (SNPs)
SNPs are tailored for people with specific health conditions or limited incomes. These plans generally include care coordination and Part D prescription drug coverage. To qualify, you must meet one of the following:
- Have a chronic or disabling health condition
- Live in an institution or require nursing care at home
- Qualify for both Medicare and Medicaid
Medicare Savings Account (MSA)
MSA plans combine a high-deductible health plan with a medical savings account. Medicare deposits money into your account, which you can use to pay for healthcare costs. Most MSA plans don’t include prescription coverage, so you may need to join a separate Part D plan.

Plan Availability Varies by Location

Not every type of Medicare Advantage plan is available everywhere. The number and variety of plans can vary significantly depending on your ZIP code. To compare options and see what’s offered in your area, visit medicare.gov/plan-compare and enter your location.

Costs of Medicare Advantage (Part C)

The cost of a Medicare Advantage plan can vary widely depending on the type of plan you choose—whether it’s an HMO, PPO, PFFS, or SNP. Some of these plans may charge a monthly premium, while others may offer coverage for as little as $0 per month.

No matter which Part C plan you select, you’ll still be responsible for paying your Medicare Part B premium. In some cases, the Advantage plan may help pay part or all of your Part B premium.

Here’s how it breaks down by plan type:

HMO, PPO, PFFS, and SNP plans may have monthly premiums and varying co-pays depending on the services you use.
MSA plans don’t charge an extra premium for the Part C plan itself, but you’re still responsible for your Part B premium.

All Medicare Advantage plans also come with cost-sharing features like co-pays and coinsurance, which differ from plan to plan.

Annual Spending Cap

One big benefit of Medicare Advantage is that it includes a limit on how much you’ll pay out of pocket for covered medical services each year. For 2025, the federal maximum out-of-pocket limit for Part C plans is $9,350 (this doesn’t include prescription drug expenses).

Once you hit that spending limit, your plan will cover 100% of eligible medical costs for the rest of the year.

Part D: Prescription Drug Coverage

Medicare Part D helps cover the cost of prescription medications. These plans are offered by private insurance companies and can either be added to Original Medicare or included in some Medicare Advantage (Part C) plans.

You’re not required to sign up for Part D—but if you don’t have drug coverage from another source, enrolling can help you avoid major out-of-pocket costs later.

Just like Medicare Advantage, the availability of Part D plans depends on where you live. Each plan has its own list of covered drugs (called a formulary), cost-sharing rules, and participating pharmacies, so it’s important to compare options in your area.

Medigap: Supplemental Insurance for Medicare

Original Medicare doesn’t cover everything. That’s where Medigap comes in. Medigap plans are sold by private insurers and help pay for things like deductibles, copays, and coinsurance that you’d otherwise have to pay out of pocket.

To be eligible for a Medigap plan, you must:

Be enrolled in Medicare Parts A and B
Not be enrolled in a Medicare Advantage (Part C) plan
Pay a monthly premium to the Medigap provider (in addition to your Part B premium)
Choose a plan from an insurer that’s licensed to sell in your state

👉 You can compare Medigap plans in your area by visiting: Medicare.gov Medigap Tool

When Can You Enroll in Medicare?

Medicare offers several enrollment windows, depending on your situation:

Initial Enrollment Period (IEP)
This 7-month window begins 3 months before the month you turn 65, includes your birthday month, and extends 3 months after. Signing up during this time helps you avoid late penalties and delays in coverage.
General Enrollment Period (GEP)
Missed your IEP? You can sign up between January 1 and March 31 each year, but your coverage won’t start until July 1, and you could owe penalties.
Annual Enrollment Period (AEP)
From October 15 to December 7, you can change your Medicare Advantage or Part D plan. This is your yearly opportunity to review your needs and switch plans if necessary.

Medicare Tips for Pre-Retirees

Approaching 65? Now’s the time to prepare.

Even if you’re still working or have retiree health coverage, it’s smart to understand how and when to enroll in Medicare to avoid penalties and gaps in care.

Most people benefit from enrolling during their Initial Enrollment Period. You can sign up online at Medicare.gov or through the Social Security Administration at ssa.gov or by calling 1-800-772-1213.

What If You Delay Enrollment?

Putting off Medicare can cost you:

Part B late enrollment penalty: You’ll pay 10% more for each 12-month period you delay enrollment—for life.
Part D penalty: You’ll owe a permanent penalty if you go 63 days or more without prescription drug coverage after your IEP ends.

Unless you qualify for an exception (such as having employer coverage), it’s usually best to enroll as soon as you’re eligible.

Still Working at 65? Here’s What to Know

If you or your spouse is still working and covered by an employer health plan, you may be able to delay Medicare enrollment without penalty—as long as:

The employer has 20 or more employees, and
The coverage is considered creditable (equal to or better than Medicare)

Once that coverage ends, you’ll have an 8-month Special Enrollment Period (SEP) to sign up for Medicare without facing late fees.

Helpful Timeline: Preparing for Medicare at 65

Here’s how to stay on track as your Medicare eligibility approaches:

12 Months Before Turning 65

Learn the basics of Medicare
Talk to your employer’s HR department if you’re still working
Create a Medicare.gov account

6 Months Before

Review your current insurance and compare it with Medicare options
Estimate potential costs for Parts A, B, C, and D

3 Months Before

Enroll in Medicare to avoid delays or penalties
Choose between Original Medicare and Medicare Advantage
Decide if you need a Part D drug plan or a Medigap policy

Medicare for People Under 65

Medicare isn’t just for those age 65 and older. If you’re younger and living with a disability or certain medical conditions, you may qualify for Medicare before your 65th birthday. Knowing your eligibility and coverage options can help you avoid costly healthcare gaps.

Who Qualifies for Medicare Under 65?

You may be eligible for Medicare under age 65 if you meet one of the following conditions:

You receive Social Security Disability Insurance (SSDI):
You’ll automatically be enrolled in Medicare after receiving SSDI benefits for 24 consecutive months.
You have End-Stage Renal Disease (ESRD):
You may qualify for Medicare sooner, starting after your fourth month of dialysis. Coverage may begin even earlier if you receive a kidney transplant or train for at-home dialysis.
You have Amyotrophic Lateral Sclerosis (ALS):
If you’re diagnosed with ALS (Lou Gehrig’s disease), you’ll qualify for Medicare as soon as your SSDI benefits begin—no waiting period required.

What Medicare Covers If You’re Under 65

If you qualify for Medicare early, you’ll generally receive the same Part A (hospital) and Part B (medical) benefits as those over 65. That includes:

Inpatient hospital care
Outpatient doctor visits
Preventive services
Durable medical equipment

You’ll also have the option to add Part D (prescription drug coverage) or enroll in a Medicare Advantage plan.

Things to Know About Costs and Supplemental Coverage

Although Medicare coverage is mostly the same, younger beneficiaries often face a few unique challenges:

Medigap plans may be limited:
Private insurance companies are not required to offer Medigap (Medicare Supplement Insurance) to people under 65 in many states. Some states do mandate at least one plan, but costs can be higher, and options are fewer.
Premiums may be higher:
If you’re under 65 and qualify due to a disability, some Medicare plans—especially Medigap or Medicare Advantage options—may come with higher premiums than those available to older adults.

Other Health Insurance Options If You Don’t Qualify Yet

If you’re under 65 and don’t qualify for Medicare yet, you still have ways to get coverage and avoid high medical bills:

Medicaid

Medicaid offers free or low-cost health insurance to people with limited income. It can help cover doctor visits, hospital care, and even long-term services in some cases.

Eligibility varies by state, but many have expanded Medicaid under the Affordable Care Act (ACA), making it easier to qualify.
Medicaid can serve as a temporary safety net until you become eligible for Medicare.

ACA Marketplace Plans

If you don’t qualify for Medicaid or Medicare, you can shop for health insurance through the ACA Marketplace at HealthCare.gov.

These plans are income-based and may come with premium subsidies or cost-sharing assistance.
There’s a range of plan types—from basic to comprehensive—so you can choose one that fits your needs and budget.
Open Enrollment runs from November 1 to January 31, though special enrollment may be available if you experience a major life change.

Continued Coverage Options

If you’ve recently lost your job or are in between jobs, you may be able to keep your existing health insurance temporarily through your former employer. This is usually done through COBRA, which allows you to maintain the same job-based coverage for a limited period—typically up to 18 months.

However, it’s important to note that under COBRA, you must pay the full premium yourself, including the portion your employer used to cover. That means your monthly costs could be significantly higher than they were while you were employed.

Still, COBRA may be a valuable option if:

You want to keep your current doctors and care network
You need uninterrupted coverage during a transition
You’re waiting for Medicare or another plan to begin

While COBRA offers consistency, it’s important to compare it with other available options—like Medicaid or ACA Marketplace plans—which might offer lower costs or better benefits depending on your income and needs.