I. What Medicare Part B Covers

In many ways, Medicare Part B is the largest and most complex part of Original Medicare. The services it covers touch nearly every part of seniors’ health, and the coverage it provides pays for some of the most expensive treatments recipients get outside of the hospital. Some of the major items it covers are considered essential health services.

Medically Necessary Services

Part B pays a large portion of the cost of medically necessary procedures and treatments performed at a doctor’s office. Medically necessary services are considered eligible for coverage if they are prescribed by a doctor or other practitioner to diagnose or treat a medical condition. While exceptions exist, and only a program specialist can give a definitive answer about what Part B covers, most of the services performed in a medical office are covered.

Preventive Care Services

Medicare Part B provides for regular examinations by a doctor, as well as needed diagnostic tests ordered by a medical practitioner. Physical examinations, X-rays, MRIs, and other diagnostic services are included under normal Part B coverage. To be eligible for payment, services must be provided at the direction or order of a physician who accepts Original Medicare.

Clinical Research

Medicare Part B services include clinical research. This covers many of the experimental procedures and treatments conventional insurance often declines to pay for. Seniors who wish to try medication and medical treatments that have yet to win full approval may be able to participate in all stages of medical research at reduced or no cost.

Ambulance Services

The cost of ambulance services varies enormously across the United States. In some areas, such as Lima, Ohio, local taxes cover uninsured costs of necessary ambulance services. In other places, the cost can range from $400 to $1,200 for the trip, plus mileage charges. Medicare Part B pays some or all of fthe cost of ambulance transportation, as well as for the treatments administered en route.

Durable Medical Equipment

Durable medical equipment includes the walkers, shower chairs, mobility devices, and other needed appliances seniors use to manage disabilities and medical conditions. Medicare Part B pays for many of these devices, as well as various at-home monitors and other alert systems that can help manage an emergency and assist seniors with living independently at home.

Mental Health

Medicare Part B provides for mental health treatment, which is considered an essential field of public health. Mental health services include talk therapy, group therapy, and medical treatment for mental, behavioral, and addiction issues.


Medicare Part B does not normally pay for inpatient services, such as surgery and pre- and post-operative treatments in the hospital. Inpatient addiction and mental health services, such as substance abuse rehab, are provided for by Original Medicare, but coverage is generally handled under Part A, as is hospice care.


Part B is primarily intended for outpatient services. Office visits and remote care, such as home visits and video conferences, are also typically included in Part B coverage. Some in-home care services are included in Part B, as are various needed long-term treatments, such as dialysis.

Partial Hospitalization

Partial hospitalization refers to inpatient care that does not necessarily include overnight stays in the medical facility. Certain mental health services, and many senior daycare programs, are included under Part B. Partial hospitalization is loosely described as services recipients can check in for in the morning and return home from before the end of the day. Part B pays for these services, as it does for regular outpatient care.

Limited Outpatient Prescription Drugs

Prescription drugs are most commonly paid for by Medicare under Part D, but both Parts A and B also pay for some medications under limited circumstances. Part A generally pays for medications administered while in the hospital, while Part B provides similar coverage for drugs administered in the doctor’s office. As a rule, drugs covered under Part B are those that cannot be taken independently by patients but which are directly administered by a medical practitioner. An example of Part B covered medication could be a topical anesthetic administered as part of an outpatient surgery or IV antibiotics that have to be delivered in the medical office.

II. Eligibility for Medicare Part B

All seniors who are eligible for Medicare Part A are automatically qualified for Part B, and they have the option to sign up for benefits and pay a monthly premium. People who are not eligible for Part A coverage but who wish to take part in Part B may still be able to apply. To be eligible for Part B under these circumstances, beneficiaries must be aged 65 and over and U.S. citizens or lawful residents who have resided in the United States for a continuous 24 months prior to application.

Seniors who receive railroad pensions may also be automatically enrolled in Medicare Parts A and B at age 65, as can adults under age 65 who have received SSDI for at least 24 months. Adults in the United States may also be eligible for Part B coverage if they have been diagnosed with end-stage renal disease or amyotrophic lateral sclerosis, which is also known as ALS, or Lou Gehrig’s disease.

III. Enrolling in Medicare Part B

Eligible seniors are generally enrolled in Medicare Part A when they reach age 65. Because this part of Original Medicare is provided at no charge, enrollment is automatic. Part B plans do generally cost seniors a premium, and participation is voluntary. Seniors can choose to enroll in Part B as part of their initial Medicare enrollment, or they can choose to join Part B later on during an open enrollment period that runs from January 1 to March 31 each year. During this period, seniors enrolled in Part A who wish to enroll in Part B can do so during the enrollment period by submitting form CMS-40B and submitting it to a local Social Security office. Applications submitted outside of the open enrollment window can still be accepted, but beneficiaries may have to pay a penalty rate for late enrollment.

Under some circumstances, seniors can enroll in Medicare Part B outside of the enrollment window without a penalty premium. Special enrollment periods (SEPs) typically begin when something about the beneficiary’s existing coverage changes. An example of this may be the loss of employer-based coverage due to retirement or the expiration of an existing plan. An SEP can also begin for seniors whose present carrier goes bankrupt and can no longer provide benefits for its members. In the event of a loss of coverage, the SEP begins on the first day of the first month of eligibility and runs for eight months. Seniors who go eight continuous months without coverage are no longer eligible for an SEP, and they must wait for an open enrollment period to again review their coverage.


Do seniors have to enroll in Medicare Part B?

Enrollment in Part B is voluntary for most seniors, but delaying entry can cost extra money later on. Unless a senior is eligible for a special enrollment period, a penalty fee may be added to the monthly premium if the benefits application is delayed.

What does Medicare Part B cost?

Costs for Medicare Part B vary somewhat between recipients and between areas of the country. For seniors who earn less than $85,000 a year from all sources combined, or $170,000 a year for married couples, the 2019 monthly premium held at an average of $135.50. Beneficiaries with higher incomes pay between $189.60 and $460.50 a month for Part B coverage. Part B also carries a copayment that is due and payable at the point of service. The annual spend-down amount for Medicare is $185, after which benefits kick in and Original Medicare starts paying costs. Seniors who earn less than $1,012 a month may be excused from these extra charges, as well as the monthly premium for Part B.

Is there an alternative to Part B that provides the same coverage?

Seniors who do not wish to participate in Part B have the option to choose alternative coverage under a program called Medicare Advantage. Medicare Advantage, also called Part C, provides all of the same benefits available under Parts A and B, combined under a single premium that can also include some optical and prescription drug coverage. Medicare Advantage plans vary in availability and price around the country, but information about options is generally available at each state’s health care exchange website.

What is the co-payment due at the point of service?

After the annual spend-down amount of $185 has been paid, Medicare Part B begins providing coverage for outpatient services. Beneficiaries are expected to pay 20% of their total cost at the time of service, after which the rest of their bill is paid by Medicare. To authorize a direct payment from Medicare Part B, health care providers must be willing to accept assignment or agree to charge only the rates negotiated by Medicare.

Do all providers accept Medicare rates for Part B services?

Not every provider accepts assignment of Medicare rates. Those who do not participate in the preferred provider program may still bill Medicare for Part B services, as well as the 20% copayment. In addition to this, non-preferred providers can charge beneficiaries as much as 15% more than the usual copayment at the point of service. This amount must be accepted as payment in full, with further costs forwarded to Medicare for payment.