2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Digestive System 520-579 > Appendicitis 540-543 > ICD-9-CM Diagnosis 540 Acute appendicitis 540 is a non-specific code that cannot be used to specify a diagnosis ICD-9-CM Diagnosis 540.0 Acute appendicitis with generalized peritonitis 540.0 is a specific code that can be used to specify a diagnosis 540.0 contains 7 index entries ICD-9-CM Diagnosis 540.1 Acute appendicitis with peritoneal abscess 540.1 is a specific code that can be used to specify a diagnosis 540.1 contains 21 index entries ICD-9-CM Diagnosis 540.9 Acute appendicitis without peritonitis 540.9 is a specific code that can be used to specify a diagnosis 540.9 contains 1 index entry