What does annual deductible mean for health insurance?

The annual deductible is the aggregate maximum amount that the insurance policy requires the insured(s) to pay over the course of a year in deductibles.

Stated otherwise, a deductible will normally be incurred for each physician's visit, medical test, or other procedure. There may come a point however, during the course of the year, when the total of all of those deductibles meet or exceed the annual deductible (specified in the policy). At that point the annual deductible will have been met and until the start of the new policy year, no further individual deductibles will have to be paid.