Abstract: A system and method utilizing deep clinical knowledge represented as a knowledge-graph to complement and enhance Natural Language Processing (NLP) for efficient and high-quality computer assisted coding of medical text. One embodiment utilizes the International Classification of Diseases version-10 Procedural Coding System (ICD-10-PCS). The system uses multiple knowledge bases combined with direct mapping provided by the ICD-10-PCS standard to enhance the coverage of assigned code. The system identifies ICD-10-PCS code considering hierarchical mapping and identifies the code by individual ICD-10-PCS character.