In this short demo, I walk through how to look up GERD in the ICD-10-CM book—and explain why symptoms like chest pain don’t get coded when a confirmed diagnosis is documented. This is a very entry-level, introductory example meant to show how ICD-10-CM code lookup works. Real-world medical coding is much more complex and involves guidelines, documentation review, payer rules, and clinical judgment. Coders use a mix of tools, including paper code books, eBooks, and specialized coding software, de