When we use a negative construction (with not) in the main clause, until means 'not before'. I won't (will not) start cooking until you come home. until three kilometres.
Medicare Part A is hospital insurance that covers inpatient hospital care and certain home care. Medicare Part A is usually free if you or your spouse paid Medicare taxes while working. If not, it can cost up to $413 each month in 2017. Hospital and skilled nursing facility stays come with deductibles and co-insurance.
Part A doesn't cover care from doctors who treat patients in the hospital. Those doctor bills -- such as from a surgeon, radiologist, oncologist, or primary care physician -- are covered instead by Medicare Part B. Nor does Part A cover emergency room care; that, too, is covered under Part B.