Question: North Carolina Subscriber Answer: Don't forget to attach these ICD-9 codes to G0105 to prove medical necessity for the service: • 555.0 -- Regional enteritis; small intestine • V16.0 -- Family history of malignant neoplasm; gastrointestinal tract. Why it matters: High-risk criteria: When your outpatient physician performs a colonoscopy screening on a Medicare patient at high risk for colorectal cancer, the patient could have one or more of the following characteristics: • a close relative (sibling, parent or child) who has had colorectal cancer or an adenomatous polyp • a family history of familial adenomatous polyposis • a family history of hereditary nonpolyposis colorectal cancer • a personal history of colorectal cancer • a personal history of adenomatous polyps • inflammatory bowel disease, including Crohn's disease and ulcerative colitis.