A deductible is the amount of annual medical expenses that a health plan member must pay before the plan will begin to cover expenses. For example, if your plan has a $500 deductible, you will pay the first $500 of your medical expenses before your health plan begins paying the expenses. Only expenses for covered services apply towards the deductible. For example, if you paid $100 for a visit to a chiropractor but the plan does not consider chiropractic care a covered expense, then the $100 will not apply toward your annual deductible.