Since Medicare only picks up 55% of my care costs, will my AARP policy cover the remaining amount?

Your Medicare supplemental policy with AARP is commonly called a Medigap policy. All Medigap policies are coordinated with Medicare benefits and are intended to pay some -- but not all -- of the health care expenses that Medicare doesn't pay. The specific things your Medigap policy covers, and the amounts it pays, depend on the terms of the policy itself, which must be one of the standardized policies governed by federal rules.

In general, for whatever specific types of medical care your Medigap policy covers, it only pays if Medicare also pays. In other words, if for any reason Medicare does not cover a service at all, neither will your Medigap policy. So, for many health care costs -- such as non-prescription medicines, some medical supplies, physical therapy over a yearly limit, elective procedures, non-covered alternative medicine -- you will receive no payments at all from either Medicare or your Medigap policy. For medical bills that Medicare does cover, your Medigap policy will usually pay the 20 percent of doctor and other outpatient bills that Medicare does not pay, as well as certain other Medicare copayments and deductibles (which ones depends on which type of Medigap policy you have).

The figure of 55 percent of health care costs Medicare pays is an average, not a rule. For some people who have high medical bills for therapies, alternative medicine, and over-the-counter drugs that Medicare doesn't cover, this figure may be even lower. For most people, though, it's slightly higher. But whatever the exact figure turns out to be for you in any year, your Medigap policy will pay a large chunk of your medical expenses that Medicare covers but doesn't pay all of, and nothing at all for things Medicare doesn't cover.