Ace the Codes: Master the 2026 Medical Coding Practice Test with Flair!

The main role of the NCHS (National Center for Health Statistics) in the context of ICD-9-CM (International Classification of Diseases, 9th Revision, Clinical Modification) is to maintain and update the diagnosis portion of the coding system. Option A is incorrect because the NCHS does not arrange codes based on alphabetical order, but rather follows a specific coding structure and guidelines. Option B is incorrect because the NCHS focuses on the diagnosis portion of the coding system, while option C is incorrect because training and certification for coding professionals is typically provided by organizations and institutions other than the NCHS. Therefore, D is the correct answer as the NCHS is responsible for updating and maintaining the diagnosis portion of ICD-9-CM, which is a critical aspect of the coding system.