Medical Billing & Coding professionals keep records, calculate patient charges and review files. Duties include reviewing records, calculating changes to patient procedures and services and prepare itemized statements and submitting claims to their party payees. Certified Specialists also determine codes for physician's procedures and diagnosis ICD-9 and CPT-4 protocols for third party billing purposes. Students go through an externship in a doctor's office, clinics, hospitals or laboratories. The student will gain an understanding of medical insurance and completing medical insurance forms, the roles of a medical office team, and the principles of procedure and diagnosis coding.