- Medical billing companies handle the process of submitting claims to insurance companies and getting paid for physicians' services, as the process is lengthy, complicated, and involves many rules and regulations. - There are three main parties in medical billing - the physician, the insurance company, and the patient. Medical billing companies work to maximize collections for physicians while complying with insurance company rules and not penalizing patients. - The main functions of medical billing companies are to process patient information and file claims with private insurance companies and government programs like Medicare and Medicaid in order to get healthcare providers paid on time.