Medicare Part B (medical insurance) is part of Original Medicare and covers medical services and supplies that are medically necessary to treat your health condition.
This part of Medicare covers doctor visits, lab tests, diagnostic screenings, medical equipment, ambulance transportation, and other outpatient services.
Unlike Part A, Part B involves more costs, and you may want to defer signing up for it if you are still working and have insurance through your job or are covered by your spouse’s health plan. But if you don’t have other insurance and don’t sign up for Part B when you first enroll in Medicare, you’ll likely have to pay a higher monthly premium for as long as you’re in the program.