Anesthesia is the administration of a drug or gas to induce partial or complete loss of consciousness. Services involving administration of anesthesia should be reported by the use of the Current Procedural Terminology (CPT) anesthesia five-digit procedure code plus modifier codes.

 Surgery codes are not appropriate unless the anesthesiologist or Qualified Nonphysician Anesthetist is performing the surgical procedure. An anesthesiologist, Qualified Non physician Anesthetist or an Anesthesia Assistant (AA) can provide anesthesia services. The anesthesiologist and the Qualified Non physician Anesthetist can bill separately for anesthesia services they personally perform.

 In cases of medical direction, both the anesthesiologist and the Qualified Non physician Anesthetist would bill Medicare for their component of the procedure. Each provider should use the appropriate anesthesia modifier.

The emergency department is usually found in a hospital or other primary care center.

Due to the unplanned nature of patient attendance, the department must provide initial treatment for a broad spectrum of illnesses and injuries, some of which may be life-threatening and require immediate attention. In some countries, emergency departments have become important entry points for those without other means of access to medical care.

The emergency departments of most hospitals operate 24 hours a day, although staffing levels may be varied in an attempt to reflect patient volume.