A deductible is the amount you must pay out of pocket for covered healthcare services before your insurance starts contributing to costs. Until you reach this amount, you are responsible for paying the full cost of services, except for those that may be covered before the deductible, such as preventive care. Once you meet the deductible, your insurance begins to share costs through co-pays or co-insurance. Deductibles reset annually, and the specific amount varies by plan. Premiums and certain expenses, like co-pays, may not count toward the deductible, depending on your policy.