Key Takeaways

• Medicare Part B primarily covers outpatient services, but there are many exceptions and limitations that can result in unexpected costs or denials.

• Knowing the difference between what’s covered and what’s not under Part B in 2025 can help you avoid billing surprises and coverage delays.

The Basics: What Part B Covers

Medicare Part B is commonly described as the part of Medicare that pays for outpatient care. That includes things like:

• Doctor visits (whether in a hospital or clinic setting)

• Preventive services like screenings and vaccines

• Durable medical equipment (DME) like walkers or wheelchairs

• Diagnostic tests, including bloodwork, X-rays, and MRIs

• Some home health services

• Outpatient mental health care

But even though these categories are broad, coverage isn’t automatic for every service or item within them. Each benefit often comes with its own fine print and eligibility conditions.

When “Outpatient” Doesn’t Mean What You Think

It’s easy to assume that anything done outside an overnight hospital stay should fall under Part B. But Medicare’s classification system can lead to surprises:

• Observation Status: If you’re in the hospital for several hours or even days but are officially under “observation” and not admitted as an inpatient, Part B (not Part A) covers the stay. That means you may face higher out-of-pocket costs for hospital services.

• Same-Day Surgery Centers: Procedures done at ambulatory surgical centers are covered under Part B, but costs can differ depending on where the procedure is done.

Understanding how Medicare classifies your care—not just where you receive it—is key to anticipating how it’s billed.

Services That Require Prior Authorization or Specific Conditions

In 2025, Medicare Part B continues to require prior authorization for certain procedures and equipment. These include, but are not limited to:

• Power wheelchairs

• Certain advanced imaging tests (e.g., MRIs, CT scans)

• Repetitive scheduled non-emergency ambulance transport

Medicare may also require your provider to prove that the service is “medically necessary,” which isn’t always the same as useful or recommended.

Before undergoing any service that falls into these categories, it’s crucial to:

• Confirm that your provider is enrolled and participating in Medicare

• Ask whether pre-approval or documentation is needed

• Check that the medical condition justifying the service meets Medicare’s criteria

What Medicare Part B Doesn’t Cover

Just as important as knowing what’s covered is understanding what’s excluded. Part B does not cover:

• Most prescription drugs (unless administered in a clinical setting)

• Routine dental, vision, or hearing care

• Long-term custodial care

• Cosmetic procedures

• Care received outside the U.S., except in very limited circumstances

To address these gaps, many beneficiaries consider enrolling in supplemental coverage or other Medicare options. However, any such decision should be based on your specific medical needs and financial situation.

Preventive Services Under Part B

Medicare Part B places a strong emphasis on prevention. In 2025, the following preventive services are available with no coinsurance when certain conditions are met:

• Annual wellness visit

• Flu, pneumonia, and COVID-19 vaccines

• Screenings for cancers (e.g., colorectal, breast, prostate)

• Cardiovascular disease screenings

• Diabetes prevention and self-management training

However, services must be performed by a provider who accepts Medicare assignment, and you must meet the eligibility criteria for each service. For example, certain cancer screenings are only covered if you’re within a specific age group or risk category.

Understanding the Costs You’re Responsible For

Even with Medicare Part B coverage, you’ll still face out-of-pocket costs in 2025:

• Monthly Premium: The standard premium in 2025 is $185. Higher-income individuals may pay more.

• Annual Deductible: You pay the first $257 of covered services each year.

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

These costs apply whether you receive services at a doctor’s office, hospital outpatient facility, or another approved site. Some exceptions apply, such as for clinical lab services, which often have no coinsurance.

Coverage Limits for Therapy and Mental Health

Therapy services, including physical, occupational, and speech therapy, are covered under Part B when deemed medically necessary. However, providers must regularly document the need for continued treatment. If Medicare suspects that treatment has become maintenance rather than medically necessary, payment can be denied.

For outpatient mental health care, Part B covers:

• Psychotherapy

• Diagnostic evaluations

• Medication management

• Services provided by psychiatrists, clinical psychologists, and clinical social workers

Visits must be with eligible providers, and the same cost-sharing applies—20% coinsurance after the deductible.

Telehealth: What Still Counts Under Part B

In response to past public health emergencies, Medicare expanded telehealth services. In 2025, many of those expansions continue. Under Part B, you may still be eligible for:

• Mental health counseling via video call

• Chronic disease management

• Annual wellness visits

However, some services are returning to pre-pandemic restrictions. For instance, originating site requirements may apply again, meaning you must be in a rural area or a medical facility to access certain services.

Always confirm with your provider that the service qualifies for Medicare reimbursement under current rules.

Timing and Enrollment Still Matter

You typically enroll in Medicare Part B during your Initial Enrollment Period, which begins three months before the month you turn 65 and ends three months after. If you delay enrollment without qualifying for a Special Enrollment Period, you may face a 10% penalty for each 12-month period you were eligible but didn’t sign up.

In 2025, you can also make changes to your Medicare coverage during:

• General Enrollment Period (January 1 to March 31)

• Open Enrollment (October 15 to December 7)

• Medicare Advantage Open Enrollment (January 1 to March 31)

Missing these windows can delay your coverage or increase your costs.

Coordination with Other Coverage

If you have other insurance—through an employer, retiree plan, or Medicaid—Medicare Part B may either be your primary or secondary payer. The order of payment matters:

• If Medicare is primary, it pays first, and other insurance picks up the rest (if covered).

• If Medicare is secondary, your other insurance pays first, and Medicare may pay all, some, or none of the remaining costs.

Check with both Medicare and your other insurance provider to understand how coordination works for you.

Don’t Assume—Verify Every Time

One of the most common mistakes beneficiaries make is assuming a service will be covered just because it was in the past. Coverage rules can change, and what one provider says is “covered” may not match Medicare’s definitions.

Before receiving any service under Part B:

• Ask your provider to verify Medicare coverage

• Request a written estimate or Advance Beneficiary Notice (ABN) if coverage is uncertain

• Keep track of your Explanation of Benefits (EOBs) and statements

Taking these steps can prevent surprise bills and disputes.

Why Paying Attention to the Fine Print Pays Off

Part B coverage looks straightforward on the surface—but it’s surrounded by asterisks. From prior authorization to coinsurance, the gaps and exceptions can be costly if you don’t plan ahead. Your best defense is staying informed and verifying coverage before receiving care.

If you’re unsure how your specific needs align with Part B benefits, get in touch with a licensed agent listed on this website. They can offer personalized support based on your situation.