Part B is Medical Insurance and covers physicians services, outpatient care, test, and supplies. (see Medicare Part B)
Part B covers 2 types of services
Medically necessary services: Services or supplies that are needed to diagnose or treat your medical condition and that meet accepted standards of medical practice.
Preventive services: Health care to prevent illness (like the flu) or detect it at an early stage, when treatment is most likely to work best.
You pay nothing for most preventive services if you get the services from a health care provider who accepts assignment.
Part B covers things like:
Clinical research
Ambulance services
Durable medical equipment (DME)
Mental health
Inpatient
Outpatient
Partial hospitalization
Limited outpatient prescription drugs
2 ways to find out if Medicare covers what you need
Talk to your doctor or other health care provider about why you need certain services or supplies. Ask if Medicare will cover them. You may need something that's usually covered but your provider thinks that Medicare won't cover it in your situation. If so, you'll have to read and sign a notice. The notice says that you may have to pay for the item, service, or supply.
Find out if Medicare covers your item, service, or supply.
Medicare coverage is based on 3 main factors
Federal and state laws.
National coverage decisions made by Medicare about whether something is covered.
Local coverage decisions made by companies in each state that process claims for Medicare. These companies decide whether something is medically necessary and should be covered in their area.
Find out more Medicare Part B Details by following this link to Medicare.Gov What Part B Covers