Final answer:
The first character of an ICD-10-CM code is always a letter. These codes are part of a system used by healthcare professionals worldwide to classify and monitor diseases and are crucial for clinical documentation, insurance billing, and health statistics.
Step-by-step explanation:
The first character of codes assigned in the ICD-10-CM (International Classification of Diseases, 10th Revision, Clinical Modification) is always a letter. ICD-10-CM is a coding system developed by the World Health Organization (WHO) to classify diseases, as well as a wide variety of signs, symptoms, abnormal findings, and external causes of injury or diseases. This system is essential for clinical purposes, as it allows for a uniform and standardized language for reporting and monitoring diseases. This coding system is not only used by clinicians but also by medical coders, billers, vital-records keepers, and epidemiologists.
To illustrate the coding system, the code for a viral infection would begin with an alphabet, such as 'B' for certain infectious and parasitic diseases, and it often continues with numeric digits that provide further detail. The code helps in processing claims for reimbursement by insurance and in recording cause of death or calculating morbidity and mortality statistics.