A medical coding specialist reviews patients’ health information and medical records and ensures that bills are paid in a timely manner. Your job duties as a medical billing specialist include data entry using medical coding software and contacting insurance companies and billing offices in hospitals and physicians’ clinics. As a medical coding specialist or health information technician, you spend most of your working hours on a computer using either the CPT or ICD-9 medical coding systems. You need to understand medical terminology, pathophysiology, and reimbursement methods to succeed in medical coding specialist jobs.