Medicare Part B: Eligibility, Coverage, and Cost
When it comes to Medicare, few pieces are as essential – and as misunderstood – as Medicare Part B.
As one half of Original Medicare, Part B is the coverage that follows you outside the hospital. It’s your lifeline to everyday medical care, from routine doctor visits to life-saving outpatient procedures.
Medicare Part B is:
- Medical insurance that covers doctor visits, outpatient services, and preventative care
- Subject to a $257 deductible, as well as various coinsurance/copay costs (usually 20% of Medicare-approved services)
- Offered at a monthly premium that is standardized based on income level
- Available to US citizens age 65 and above, and certain people with disabilities or qualifying diseases
And while it plays a vital role in keeping you healthy, it doesn’t cover everything, nor does it cap your out-of-pocket spending. That’s where pairing it with a Medigap plan can make all the difference.
Whether you’re preparing to enroll for the first time or reviewing your current Medicare benefits, understanding how Part B works is critical to making informed, confident healthcare decisions.
In this guide, we’ll explain everything you need to know – from what it covers and costs to why so many people supplement it with Medigap.
What Exactly Is Medicare Part B?
Medicare Part B is medical insurance under Original Medicare. If Part A is your safety net for hospital stays, Part B is your everyday coverage for the doctor’s office, lab tests, outpatient services, and preventive screenings.
It’s structured much like a traditional health insurance policy: you pay a monthly premium, meet a deductible, and then share costs with Medicare through coinsurance.
At its core, Medicare Part B serves two important purposes.
First, it helps cover medically necessary services – those visits, tests, and treatments you need to diagnose and treat illnesses and injuries.
Second, it places a strong emphasis on preventive care, aiming to catch potential health problems early before they become more serious or costly to treat.
Think of it this way: when you visit your doctor for your annual wellness check-up, get a flu shot at your local pharmacy, or receive physical therapy after a fall, it’s Medicare Part B that steps in to help with the bill.
What Does Medicare Part B Cover?
Medicare Part B covers an impressive range of medical services and supplies, especially those provided in outpatient or clinical settings. This includes everything from routine doctor visits to more complex care like chemotherapy or dialysis.
Medically necessary services make up the bulk of what’s covered. These are treatments and procedures your doctor deems necessary to diagnose or treat a medical condition.
For example, if you’ve been feeling unusually tired and your doctor orders blood work to check for anemia or thyroid issues, that lab work would fall under Part B.
Also covered are:
- Visits to your primary care doctor and specialists
- Diagnostic imaging, such as X-rays, MRIs, or CT scans
- Outpatient surgeries
- Durable medical equipment (such as walkers, oxygen tanks, or CPAP machines)
- Ambulance transportation in emergencies
- Mental health care, including therapy and outpatient hospitalization
- Certain medications administered in a clinical setting (like injections or infusions)
In addition to covering treatment, Part B prioritizes preventive care services to keep you well and catch conditions early.
You won’t pay anything out of pocket for most preventive services as long as you meet eligibility criteria and your provider accepts Medicare assignment.
This includes things like:
- COVID-19 vaccines and flu shots
- Cancer screenings (like mammograms and colonoscopies)
- Cardiovascular and diabetes screenings
- Depression, alcohol misuse, and glaucoma screenings
- Bone mass measurements to detect osteoporosis
- Your annual wellness visit to review and plan your preventive care for the year
Taken together, these services form a strong foundation for treating existing issues and maintaining good health.
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Pro Tip:
The fastest way to determine if testing, services, or medical equipment are eligible for Part B coverage is to use the search feature at Medicare.gov.
Enter the item or service in question to see whether it is covered by Part B.
What Medicare Part B Doesn’t Cover
Despite its broad scope, Medicare Part B does leave some noticeable gaps. Knowing what’s not covered is just as important as knowing what is, especially when it comes to budgeting for healthcare and avoiding unpleasant surprises.
One of the biggest misconceptions is that Medicare covers prescription drugs. In reality, Part B only pays for a narrow set of medications, mostly those administered in a clinical setting.
If you need prescription medications you take at home – whether for blood pressure, cholesterol, or arthritis – you’ll need a separate Medicare Part D plan for drug coverage.
Other services that fall outside Part B’s coverage include:
- Routine dental care, such as cleanings, fillings, and dentures
- Eye exams, eyeglasses, and contact lenses (unless related to cataract surgery)
- Hearing exams and hearing aids
- Long-term custodial care in nursing homes or assisted living facilities
- Medical treatment outside the U.S. (with very limited exceptions)
- Cosmetic procedures like facelifts or Botox (unless medically necessary)
- Alternative therapies such as massage or naturopathy
- Routine foot care, unless medically required due to conditions like diabetes
These exclusions highlight the importance of reviewing your coverage carefully and considering supplemental insurance if your needs go beyond what Part B provides.
What Does Medicare Part B Cost in 2025?
Medicare Part B is not free. Enrollees must pay a monthly premium, meet an annual deductible, and then share costs through coinsurance for most services.
The standard monthly premium for 2025 is $185. However, based on your tax return from two years ago, if you earn above a certain income threshold, you may be required to pay more.
This surcharge, called the Income-Related Monthly Adjustment Amount (IRMAA), can add hundreds of dollars to your monthly bill.
For example, if you’re a single filer earning $133,000, your total monthly premium will be $259.
If you earn more than $500,000, that premium rises to $628.90.
These adjustments also apply to married couples filing jointly, based on combined income.
Here’s a helpful breakdown of the 2025 Medicare Part B monthly premiums based on your income and tax filing status – use these charts to see if an Income-Related Monthly Adjustment Amount (IRMAA) might apply to you.
For Individuals Filing as Single
| 2023 Income (MAGI) | IRMAA (Monthly Adjustment) | Total Monthly Premium |
|---|---|---|
| $106,000 or less | $0.00 | $185.00 |
| $106,001 – $133,000 | $74.00 | $259.00 |
| $133,001 – $167,000 | $185.00 | $370.00 |
| $167,001 – $200,000 | $295.90 | $480.90 |
| $200,001 – $499,999 | $406.90 | $591.90 |
| $500,000 or more | $443.90 | $628.90 |
For Married Couples Filing Jointly
| 2023 Joint Income (MAGI) | IRMAA (Monthly Adjustment) | Total Monthly Premium |
|---|---|---|
| $212,000 or less | $0.00 | $185.00 |
| $212,001 – $266,000 | $74.00 | $259.00 |
| $266,001 – $334,000 | $185.00 | $370.00 |
| $334,001 – $400,000 | $295.90 | $480.90 |
| $400,001 – $749,999 | $406.90 | $591.90 |
| $750,000 or more | $443.90 | $628.90 |
Note: These premiums are based on your Modified Adjusted Gross Income (MAGI) reported on your 2023 tax return and used to calculate your 2025 premiums. If your income has recently changed (for example, due to retirement), you may be eligible to request a reconsideration to reduce your IRMAA amount by submitting a form and documentation to the Social Security Administration.
In addition to your Part B monthly premium, you’ll pay a $257 annual deductible in 2025. Once you meet this deductible, Medicare typically covers 80% of the cost of services, and you pay the remaining 20%, with no annual limit.
That’s worth emphasizing: there is no out-of-pocket maximum with Original Medicare. This means if you need frequent care or face a serious health issue, your costs can skyrocket.
Why Pairing Part B with a Medigap Plan Makes Sense
Here’s where Medigap (also called Medicare Supplement insurance) can be a game-changer. It’s not just a “nice-to-have” for some people; for many, it’s the safety net that makes Medicare workable and predictable.
Because Medicare Part B only covers 80% of most services and has no out-of-pocket limit, many enrollees choose to buy a Medigap plan to help cover the difference.
These plans are sold by private insurers and designed to fill the “gaps” in Original Medicare, including:
- The 20% coinsurance for Part B services
- Hospital coinsurance, skilled nursing facility costs, and hospice care under Part A
- Emergency care received during foreign travel (for some plans)
- Excess charges from providers who don’t accept Medicare assignment
Several standardized Medigap plans are available, like Plan G, Plan N, and Plan A, each offering a different level of coverage. The most popular plan, Plan G, covers almost everything except the Part B deductible.
After you pay that, nearly all your Medicare-approved expenses are paid in full.
For instance, if you undergo an outpatient surgery costing $5,000, you’ll owe 20% of that, or $1,000, out of pocket.
But with a Medigap Plan G, for example, once you’ve met the $257 deductible, your plan would cover that $1,000 entirely.
Medigap plans also give you the freedom to see any provider who accepts Medicare – no networks, no referrals required. Many even offer coverage for emergency care outside the U.S., which is not included in Part B.
Ultimately, pairing Part B with a Medigap plan is about financial protection and peace of mind. It helps you plan ahead, manage your healthcare expenses, and avoid surprise bills.
Who Is Eligible for Medicare Part B?
Understanding whether you qualify for Medicare Part B is an important first step in building your Medicare coverage. The good news is that eligibility is relatively broad, and most people will qualify automatically when they turn 65.
However, special circumstances, such as disability or certain medical conditions, can also make you eligible even earlier.
Let’s walk through the key pathways to eligibility, including age-based qualification, disability-based coverage, and how residency or citizenship plays a role.
Age-Based Eligibility
The most common way people become eligible for Medicare Part B is by aging into the system.
If you’re turning 65, you’re likely eligible for Part B if:
- You’re a U.S. citizen, or
- You’re a lawfully admitted permanent resident who has lived in the United States for at least five continuous years
For those who already receive Social Security retirement benefits or Railroad Retirement Board benefits by the time they turn 65, enrollment in both Medicare Part A and Part B is typically automatic. You’ll receive your red, white, and blue Medicare card in the mail about three months before your 65th birthday.
You won’t need to do anything to start your coverage unless you want to delay it (for example, if you’re still covered under a group health plan through an employer or spouse).
However, if you are not receiving Social Security or RRB benefits, you’ll need to actively sign up for Medicare during your Initial Enrollment Period. This seven-month window begins three months before your 65th birthday, includes your birthday month, and continues for three months after.
Disability-Based Eligibility
Medicare Part B isn’t just for people over 65. If you’re under age 65 but living with a disability or certain serious medical conditions, you may still qualify.
Here’s how:
- Social Security Disability Insurance (SSDI) recipients become eligible for Medicare after they’ve received disability benefits for 24 consecutive months. At that point, Medicare coverage – including Part B – is typically automatic, and you’ll receive your enrollment information in the mail.
- If you’re diagnosed with Amyotrophic Lateral Sclerosis (ALS – also known as Lou Gehrig’s disease) you’re eligible for Medicare immediately. There is no 24-month waiting period. Your Medicare coverage, including Part B, begins the same month your Social Security disability benefits begin.
- Individuals with End-Stage Renal Disease (ESRD) – a permanent kidney failure condition requiring dialysis or a transplant – can also qualify for Medicare. The timeline for when coverage begins can vary based on your treatment plan (such as whether you’re receiving dialysis at home or in a facility), but Medicare Part B is available and highly recommended to help cover outpatient dialysis and kidney-related services.
Citizenship and Residency Requirements
No matter your age or medical condition, Medicare Part B eligibility also depends on your legal status in the United States.
You must be either a U.S. citizen or a lawful permanent resident (green card holder) who has resided in the U.S. for at least five continuous years.
If you meet this criterion and turn 65, you can enroll in Part B. Remember that you do not need to have paid into Medicare through payroll taxes (as is required for premium-free Part A) to qualify for Part B.
However, if you didn’t meet the work requirement for free Part A, you must pay a monthly premium for Part A and Part B.
When and How to Enroll in Medicare Part B
Most people enroll in Part B around their 65th birthday, during a seven-month Initial Enrollment Period (IEP) that begins three months before the month you turn 65, includes your birthday month, and ends three months afterward.
To avoid delays or penalties, it’s best to enroll during the first three months of your IEP.
Waiting can lead to gaps in coverage – or worse, a late enrollment penalty that increases your premium by 10% for every 12-month period you delayed enrollment without other creditable coverage.
If you miss your IEP, you can enroll during the General Enrollment Period from January 1 to March 31 each year, though coverage won’t begin until July. You may also qualify for a Special Enrollment Period if you’re still working and have employer coverage, or if you lose that coverage later on.
Enrolling is easy: you can apply online at SSA.gov, call Social Security, or visit your local SSA office.
How Do You Pay for Medicare Part B?
Paying for Medicare Part B is a straightforward process, but the method depends on whether you’re already receiving Social Security or Railroad Retirement Board (RRB) benefits.
Let’s go over both.
If You Receive Social Security or Railroad Retirement Benefits
If you’re already drawing monthly benefits from Social Security or the RRB, Medicare makes things simple: your Part B premium is automatically deducted from your monthly check.
You won’t need to take any action to initiate this – once your Medicare coverage begins, the premium will be withdrawn each month and noted on your benefit statement.
This automatic deduction helps ensure your coverage remains active without the need to manage monthly bills. It’s one less thing to keep track of as you transition into retirement.
If You Do Not Receive Social Security or RRB Benefits
If you’re enrolled in Medicare Part B but haven’t started receiving retirement benefits, you will be billed directly for your premium. In this case, Medicare sends you a paper invoice called the “Medicare Premium Bill” (Form CMS-500) on a quarterly basis.
Your bill will arrive once every three months and include the premium amount for the upcoming quarter. For example, if your standard premium is $185 per month in 2025, you’ll be billed $555 for three months of coverage.
You have several payment options available:
- Online via Medicare.gov: The fastest and most secure method is to pay online using a debit or credit card or by linking your bank account. You can do this through your secure Medicare account at Medicare.gov.
- Medicare Easy Pay: This is a free and convenient service that automatically deducts your premium each month from your checking or savings account. You can sign up by completing a form online or calling 1-800-MEDICARE.
- By mail: If you prefer to send a check or money order, you can do so using the payment coupon included with your bill. Be sure to include your Medicare number on the check to ensure it’s processed correctly.
- Through your bank’s bill pay service: Many banks offer online bill pay, allowing you to schedule recurring payments to Medicare just like any other utility or subscription service. Again, make sure your Medicare number is listed as the account number.
If your premium isn’t paid on time, Medicare will send a second notice. Continued non-payment can result in the loss of your Part B coverage, which may be difficult (and costly) to reinstate later.
Because of the potential consequences, many enrollees choose automatic payment methods like Easy Pay or bank bill pay to ensure their premium is paid on time every month.
If your income or financial situation changes, you can contact Medicare or Social Security to request premium adjustments or to explore potential savings programs, such as the Medicare Savings Program.
Can You Drop Medicare Part B?
Yes, you can drop Medicare Part B, but it’s a decision that should be made with caution.
While Part B provides essential coverage for outpatient care, there may be situations where canceling it makes sense, such as when you have employer-sponsored health insurance or Veterans Affairs (VA) benefits.
However, dropping Part B without understanding the consequences can result in late enrollment penalties, delays in future coverage, and limited access to supplemental plans.
Common Reasons Someone Might Drop Part B
People consider dropping Part B for various reasons:
- They have other health coverage: If you’re still working and have group health insurance through your employer or your spouse’s employer, you may not need Part B right away.
- They’re enrolled in VA benefits: Veterans who receive care through the VA system might feel that Part B is redundant, especially if they rarely seek care outside VA facilities.
- They’re trying to reduce expenses: The monthly premium, especially if subject to IRMAA, can be a financial burden for those on a tight budget.
Regardless of the reason, dropping Part B should only be done after careful consideration, especially because re-enrolling later may not be easy or cheap.
How to Cancel Part B
Unlike many insurance policies, you can’t simply cancel Medicare Part B online or by phone. There is a specific process you must follow.
#1. Contact the Social Security Administration and request Form CMS-1763, titled “Request for Termination of Premium Hospital and/or Supplementary Medical Insurance.”
#2. Participate in a personal interview: Before your cancellation request is processed, you’ll be required to complete an interview with a Social Security representative. This step ensures you understand what you’re giving up and the potential long-term effects.
#3. Choose an effective date: After completing the form and interview, your termination will take effect on either the first day of the following month or a future month that you select.
It’s important to keep your coverage active until your cancellation is finalized and effective. Any lapse could result in unpaid medical bills.
The Risks of Dropping Part B
Dropping Part B may provide short-term savings, but the long-term consequences can be significant:
- Late Enrollment Penalty: If you decide to re-enroll in Part B later, you may face a permanent late enrollment penalty. This penalty adds 10% to your monthly premium for every full 12-month period you were eligible for Part B but did not enroll. For example, if you waited three years to re-enroll, you would pay 30% more for the rest of your life.
- Limited Enrollment Windows: You can’t just rejoin Part B at any time. If you drop it, you’ll have to wait until the General Enrollment Period (January 1 to March 31) to re-enroll, with coverage beginning July 1 of that year. This could leave you without coverage for several months.
- Impact on Other Coverage: Dropping Part B may also make you ineligible for certain Medigap or Medicare Advantage plans. Most of these plans require continuous enrollment in both Medicare Part A and Part B to stay active.
- Out-of-pocket risk: Without Part B, you’ll be fully responsible for the cost of outpatient care, lab work, durable medical equipment, and preventive services. These costs can add up quickly and lead to financial strain.
If you have other creditable coverage – like an employer-sponsored group plan – it may be reasonable to delay or drop Part B. In that case, you may qualify for a Special Enrollment Period later that allows you to sign up without penalty when your other coverage ends.
But unless you’re absolutely certain that your alternative coverage meets Medicare’s requirements for creditable coverage, it’s wise to speak with a Medicare specialist before canceling.
Final Thoughts
From annual wellness visits and flu shots to emergency ambulance rides and cancer treatment, Part B is designed to help you access the care you need to stay healthy and active as you age.
But while its coverage is broad and essential, it’s not complete. Understanding the costs and coverage gaps – such as the lack of a spending cap, the 20% coinsurance, and exclusions like dental, vision, and prescription drugs – is critical.
These uncovered services can leave beneficiaries exposed to high and unpredictable medical bills, especially for chronic conditions or serious health events. That’s why planning beyond Part B is just as important as enrolling in it. Many people find that Medicare Part B works best when it’s part of a larger, more comprehensive strategy.
Whether that means adding a Medicare Part D plan for drug coverage or purchasing a Medigap (Medicare Supplement) policy to handle coinsurance and deductible costs, the right pairing can make Medicare far more affordable and predictable.
Medigap, in particular, has become a trusted solution for millions of Medicare beneficiaries who want to protect their finances from large or unexpected healthcare expenses. When you combine the reliability of Original Medicare with the cost-sharing protections of a Medigap plan, you create a powerful safety net that allows you to focus on your health, not your bills.
We understand that choosing how to structure your Medicare coverage can be overwhelming. There are numerous options, complex rules, and timing windows that can easily trip up even the most diligent planner. That’s where we come in.
Our team is here to help you understand Medicare and choose coverage that fits your health needs, financial goals, and lifestyle.
So, whether you’re approaching age 65, already enrolled in Medicare, or helping a loved one through the process, remember: Part B is essential – but it doesn’t have to stand alone. You deserve healthcare coverage that gives you peace of mind and the freedom to live life on your terms.
If you’re ready to explore how a Medigap plan can work alongside Medicare Part B, or if you simply want guidance on your next steps, our licensed advisors are here to help – free of charge and with no obligation.
Sources: What’s Covered | Eligibility | Costs | Enrollment
FAQs
- Can I be denied Medicare Part B?
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