What is the definition of a Medigap policy?

A Medigap policy is specifically designed to supplement Medicare by covering medical costs that are not paid for by the federal Medicare program. This includes co-payments, deductibles, and other gaps in coverage that Medicare may leave for beneficiaries. Such policies provide essential financial support for healthcare expenses, helping to reduce out-of-pocket costs for individuals who are eligible for Medicare.

The other options describe different types of insurance or coverage unrelated to the primary purpose of a Medigap policy. Dental and vision expenses, long-term care services, and prescription drug coverage are all important aspects of healthcare but fall under separate categories of insurance or plans that are not intended to supplement Medicare directly. Hence, the key characteristic of a Medigap policy lies in its role of filling the financial gaps left by Medicare, which is what makes the correct answer stand out clearly.