What is one of the surest ways for a practice to lose revenue and invite the unwanted attention of government auditors? By failing to select and document the appropriate use of modifiers to code for services provided. For example, the Office of Inspector General (OIG) has made it known that they will closely review professional billing with the use of modifier '-25.' The use of this particular modifier appeared on their radar screen, because in one recent year Medicare paid approximately 1.7 billion dollars for Evaluation and Management (E/M) services billed with modifier '-25'. The OIG feels an increase of this amount warrants further investigation to determine if these claims were billed and reimbursed appropriately. Additionally, Oklahoma Medicaid auditors are actively scrutinizing the use of modifier '-25' to a degree even more stringent than Medicare and the CPT code book's description allow. Therefore, it is important that physicians be knowledgeable in determining when it is appropriate to bill using this modifier.