Diagnostic coding of neurocognitive disorders: A roadmap to ICD-10-CM

Objective: Diagnosis coding is a core clinical competency. A basic understanding of the structure of the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), the conventions and rules for diagnosis coding, and what constitutes accurate coding, is fundamental to the clinician's knowledge base. This commentary seeks to provide a practical framework for clinicians to perform accurate diagnosis coding of neurocognitive disorders. Method: This paper: (1) summarizes the structure of the ICD-10-CM, (2) describes the rules and conventions of diagnosis coding for diagnostic categories relevant to neurocognitive disorders, (3) presents clinical examples and pragmatic recommendations to help readers improve their day-to-day use of diagnosis codes, and (4) describes limitations and discrepancies in the diagnosis coding advice for neurocognitive disorders presented within the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) and the DSM-5-TR Neurocognitive Disorders Supplement. Its content originates from the ICD-10-CM itself and its companion document, the ICD-10-CM Official Guidelines for Coding and Reporting. Conclusion: The ICD-10-CM classification scheme is logically organized and easy to navigate for users who understand its structure and rules. Many neuropsychologists rely on the DSM-5-TR diagnosis coding advice, however that advice is limited with respect to the range of diagnosis codes relevant to neurocognitive disorders and their underlying causes. Relying on the ICD-10-CM directly for diagnosis coding of neurocognitive disorders, rather than the DSM-5-TR or other secondary sources, is therefore preferable and aids clinicians in accurate diagnosis coding.