Medicare Part B Covers Doctors—But It Might Also Confuse the Life Out of You

Key Takeaways

• Medicare Part B covers a wide range of outpatient and physician services, but it comes with monthly premiums, deductibles, and coinsurance costs that are often misunderstood.

• Enrolling on time and knowing what is and isn’t covered can help you avoid late penalties, unexpected bills, and coverage gaps.

What Medicare Part B Is and Why You Likely Need It

Medicare Part B is your entry point into outpatient care under Original Medicare. It covers medically necessary services and preventive care, making it essential for anyone who visits doctors, gets lab tests, needs durable medical equipment, or requires physical therapy. If you only have Part A, you’re missing a significant portion of healthcare coverage.

In 2025, Medicare Part B continues to be optional but strongly recommended unless you have other credible coverage through an employer or union. Enrolling late can result in permanent financial penalties.

What Medicare Part B Covers in 2025

Medicare Part B covers:

• Doctor and specialist visits

• Outpatient procedures and surgeries

• Preventive services like flu shots, cancer screenings, and annual wellness visits

• Diagnostic tests (e.g., MRIs, blood work)

• Mental health outpatient care

• Durable medical equipment (DME) such as walkers or wheelchairs

• Ambulance services when medically necessary and transport to a hospital is required

These services are only covered if deemed medically necessary or listed as preventive under Medicare.

What It Doesn’t Cover

Even though Part B is extensive, there are clear exclusions:

• Prescription drugs (these are typically covered under Part D)

• Routine dental, vision, and hearing care

• Long-term custodial care

• Cosmetic procedures

• Most chiropractic care (beyond spinal adjustments)

You should consider adding other forms of coverage, such as a standalone dental or vision plan, to address these gaps.

How Much Does Medicare Part B Cost in 2025?

Part B comes with monthly premiums, an annual deductible, and 20% coinsurance for most covered services after that deductible is met.

• Monthly premium: The standard premium is $185 per month in 2025, although it may be higher based on your income from two years ago.

• Annual deductible: $257 in 2025.

• Coinsurance: After meeting the deductible, you typically pay 20% of the Medicare-approved amount for services.

If you’re a higher-income beneficiary, you may be subject to an Income-Related Monthly Adjustment Amount (IRMAA), which increases your premium based on your tax return.

Enrollment Deadlines You Can’t Afford to Miss

You can sign up for Part B during these time windows:

• Initial Enrollment Period (IEP): Starts three months before your 65th birthday month and ends three months after.

• General Enrollment Period (GEP): Runs from January 1 to March 31 each year if you missed your IEP. Coverage begins July 1.

• Special Enrollment Period (SEP): If you delayed enrollment due to credible employer coverage, you have eight months to enroll after that coverage ends.

Missing these windows can lead to late enrollment penalties, which add 10% to your monthly premium for each full 12-month period you delayed signing up without other coverage.

The Part B Late Enrollment Penalty in Detail

The penalty is not just a one-time fee. It’s a permanent addition to your monthly premium. For example, if you delay enrollment by 2 years, your monthly premium could be 20% higher for life. This penalty is cumulative and based on the length of the delay.

Avoid this by:

• Enrolling during your IEP

• Maintaining credible employer coverage if you delay

• Keeping documentation if you’re claiming a SEP

Coordination with Employer Insurance or Retiree Plans

If you’re still working past 65, you might not need to enroll in Part B immediately. Here are the rules to follow:

• If your employer has 20 or more employees, Medicare usually pays second.

• If your employer has fewer than 20 employees, Medicare becomes your primary payer and you should enroll in Part B.

For retirees with access to a retiree health plan, always confirm whether enrolling in Part B is required to maintain full coverage.

What About Medicare Advantage?

If you choose to enroll in a Medicare Advantage plan (Part C), you’re still enrolled in both Parts A and B. Part B is required, and you must continue paying the Part B premium. These plans often wrap in additional services, but again, you must be enrolled in Part B to participate.

Medigap and Why Part B Alone Isn’t Enough

Part B leaves you responsible for 20% coinsurance and has no out-of-pocket maximum. A Medigap (Medicare Supplement) plan helps cover those leftover costs, but you must already have both Part A and Part B to be eligible.

Timing matters for Medigap, too. Your six-month Medigap Open Enrollment Period starts the month you’re both 65 or older and enrolled in Part B. Missing this window could mean being denied coverage or paying more.

Part B Preventive Services You Should Actually Use

Many preventive services under Part B are covered with no coinsurance or deductible if the provider accepts Medicare assignment. These include:

• Annual wellness visit

• Cardiovascular disease screening (every 5 years)

• Mammograms (every 12 months for women 40+)

• Prostate cancer screening (every 12 months for men 50+)

• Colonoscopy (every 10 years, or more frequently if high risk)

• Depression screenings (annually)

• Flu, pneumococcal, and COVID-19 vaccines

Staying up to date with these services can help catch serious conditions early.

Outpatient Services: The 20% Trap

After the annual deductible is met, you are responsible for 20% of the cost of any outpatient service Medicare covers. There is no yearly out-of-pocket cap under Original Medicare.

This means:

• A $1,000 outpatient procedure = $200 out of pocket

• A $5,000 infusion treatment = $1,000 out of pocket

This is why many beneficiaries seek out supplemental coverage. Without it, you could be financially exposed to repeat costs.

Know Your “Medically Necessary” Limitations

Medicare will only pay for services that are considered “medically necessary.” Just because your doctor recommends something doesn’t mean Medicare will cover it.

Before you agree to a service:

• Ask if it’s covered under Part B

• Confirm your provider accepts Medicare assignment

• Consider an Advance Beneficiary Notice (ABN) if there’s uncertainty

What Is Medicare Assignment and Why It Matters

A provider who accepts Medicare assignment agrees to accept the Medicare-approved amount as full payment. This protects you from balance billing.

• Accepts assignment: You only pay the standard 20% coinsurance.

• Does not accept assignment: The provider can charge up to 15% more than Medicare’s approved rate (called the limiting charge).

Sticking with providers who accept assignment is key to avoiding unexpected costs.

What Happens if You Delay Part B and Have No Coverage

If you skip Part B and don’t have other insurance, you face:

• No coverage for outpatient care

• Out-of-pocket medical bills

• Penalties when you eventually enroll

Even if you’re healthy now, emergencies and new diagnoses can occur at any time. Skipping Part B is a gamble that could cost you far more in the long run.

Your Doctor Matters: Provider Participation Levels

There are three types of Medicare providers:

1. Participating providers – accept Medicare and assignment

2. Non-participating providers – accept Medicare but not assignment (can charge more)

3. Opt-out providers – do not accept Medicare at all (you pay the full cost)

Always ask your provider which category they fall into before scheduling any appointments under Part B.

If You Travel or Move, Your Part B Follows You

Part B coverage is nationwide. Whether you relocate to a different state or travel across the country, your outpatient coverage follows you. However, your providers must still accept Medicare.

If you’re planning to live abroad or travel long-term internationally, keep in mind that Medicare generally doesn’t cover care outside the U.S.

Why Part B Still Confuses People in 2025

Despite being in place for decades, Medicare Part B remains confusing because:

• It comes with costs

• It requires enrollment decisions

• It doesn’t cover everything

• It varies by provider participation

• It works differently with other insurance

Understanding these layers is essential to getting the most from your benefits and avoiding costly missteps.

Getting Expert Help Can Save You Time and Money

There’s no shame in feeling overwhelmed. Medicare rules are complex and often change from year to year. Speaking with someone who understands the details can help you make confident decisions.

Ready to Understand Your Part B Coverage Better?

Don’t let confusion lead to costly mistakes or gaps in coverage. Whether you’re enrolling for the first time or managing ongoing care, knowing what Part B does and doesn’t cover is essential. Reach out to a licensed agent listed on this website who can walk you through your options, costs, and supplemental coverage.