Question: Virginia Subscriber Answer: Bad news: Although Medicare considers your scenario a screening colonoscopy for high-risk, many private carriers consider the diagnosis a medical diagnosis. Good news: Many coders bill it the way you did because this is the way Medicare says you should code it. You may try a letter of appeal and attach documentation from the January 2004 CPT Assistant as well as Medicare's guidelines. You should demonstrate that this colonoscopy was screening. Obviously the error is on their part. If your patient is saying you were the one who made the error, then copy the patient on the appeal as well. Note: You can try adding V76.51 (Special screening for malignant neoplasms; colon) as a tertiary code, not as a primary one.