Reasonable and Customary Fees: The average fee charged by a particular type of health care practitioner within a geographic area. The term is often used by medical plans as the amount of money they will approve for a specific test or procedure.

Rider: A modification made to a Certificate of Insurance regarding the clauses and provisions of a policy (usually adding or excluding coverage).

Risk: The chance of loss, the degree of probability of loss or the amount of possible loss to the insuring company. For an individual, risk represents such probabilities as the likelihood of surgical complications, medications' side effects, exposure to infection, or the chance of suffering a medical problem because of a lifestyle or other choice.