Every service (test, office visit, injection, surgical procedure, etc.) in the provision of medical care has a numeric code associated with it designed to provide some commonality of terms in order that the companies who pay the claims (health insurance companies, HMOs, etc.) can identify the patient’s problem, and the service provided sufficient to allow them to pay on a predetermined basis under the care and coverage limits of an insurance plan. The codes are also used for statistical data. The CPT (Current Procedural Terminology) codes exist for an office call, an injection, an x-ray, right on to the most detailed brain surgery. International Disease Codes (ICD) are the number systems assigned for diagnoses, even patient complaints (headache, upset stomach, etc.). The combination of using these codes, ICD and CPT, tell the payer what was wrong with the patient and what service was performed.