Fraud is defined as an intentional deception resulting in injury to another. Assessment of fraud within a health plan is complex. This chapter will focus on distinguishing normal behavior patterns from those potentially fraudulent and which should trigger a more thorough review. Materials and data appropriate for such a review are discussed and applied to various scenarios. Appropriate guidelines for drawing conclusions from the information and materials reviewed are presented. After a review of this chapter, the legal nurse consultant will have a fundamental guide and standardized approach for the evaluation of cases involving potential fraud or abuse within a government or private sponsored healthcare benefit plan.