6 month repeat colonoscopy

if a patient comes in for a hi risk routine screening, coded as the G0105 with Medicare, and with a large polyp and cancerous mass found, he is sent out for removal surgery and advised to repeat colonoscopy in 6 months.... Medicare will only cover the G0105 every 24 months and wont pay the 45378 cpt code for the repeat screening with the routine diagnosis code of personal history of colon cancer, the Z85.038. is there a way to code/bill this 6 month repeat as medically necessary to avoid the patient being responsible for the coinsurance amount?

re: 6 month repeat colonoscopy

You might try doing a diagnostic and using the code for the cancerous mass. NO screening code available.