Does Medicare cover flu shots?

From Medicare.gov

If you have Medicare Part B, your flu shot is free every year (there's no co-pay and it doesn't apply toward your deductible).
The shot must be ordered by your doctor.
Your doctor must accept Medicare and not charge more than Medicare will pay. Members of Medicare Advantage Plans need to ask their health plan for details on their coverage for the flu shot (they must cover at least what Medicare does – they may cover more).
Low cost flu shots (about $10) are available at many clinics and pharmacies at the beginning of flu season.
Where can I get a flu shot?
Here are some options for getting a flu shot:

Doctor's Office
Health Departments
Pharmacies
Offices -- many offer flu shots for employees