List of the Top 5 Medical Billing Services for Small Practices. Cost savings - Outsourcing your billing services might help small practices with little staff save money on administrative expenses. Thus, outsourcing coding services to professional medical billing companies can save you hassle and time, and ensure you receive appropriate reimbursement for services provided. In this day and age, medical billing errors can be costly and time-consuming. These numbers specify the diagnoses and treatments the patient received during their visit.