Which of the following is included as a high-risk-for-error diagnosis code in the OIG toolkit?

• A. Acute heart attack
• B. Prostate cancer
• C. Acute stroke
• D. Lung cancer

Answer: (C)

High-risk-for-error diagnoses in the OIG toolkit are flagged because they’re most prone to coding or billing mistakes, guiding audits and education. Acute stroke stands out here because confirming a stroke typically depends on precise clinical documentation plus neuroimaging results, and mistakes can happen when symptoms are transient, when a prior event is misinterpreted as current, or when the specific stroke type isn’t clearly documented. This complexity increases the chance of improper payments if coding isn’t aligned with the actual clinical picture. While other serious conditions can be coded with established criteria, the diagnostic ambiguity and the billing implications around stroke make acute stroke a common target for review, which is why it’s included in the high-risk-for-error list.