Look to These Dx for CA 19-9 Immunoassay Necessity
Question: What ICD-10-CM code should I use to prove medical necessity if our provider orders a CA 19-9 blood test with CPT® code 86301? California Subscriber Answer: According to Medline, CA 19-9 (cancer antigen 19-9) is a protein that acts as a type of tumor marker, which are “substances made by cancer cells or by normal cells in response to cancer in the body.” CPT® code 86301 (Immunoassay for tumor antigen, quantitative; CA 19-9) describes a test that measures the amount of CA 19-9 in the blood. Medline goes on to note that high levels of CA 19-9 can indicate pancreatic, bile duct, colon and rectal, stomach, ovarian, and bladder cancer along with other conditions, such as pancreatitis, gallstones, bile duct disease, liver disease, and cystic fibrosis. For a useful guide to ICD-10-CM codes that Medicare sees as describing medical necessity for 86301, go to national coverage determination (NCD) 190.30 and locate the most recent PDF listing the diagnosis codes Medicare accepts for the test. There, you will find such cancer and cancer-related diagnoses as: Take note of these caveats: The current PDF also stipulates that 86301 services “are not covered for the evaluation of patients with signs or symptoms suggestive of malignancy.” In other words, you should not perform the assays on patients in an attempt to provide a positive or negative cancer diagnosis. The document also goes on to say you should only order the immunoassay “at times necessary to assess either the presence of recurrent disease or the patient’s response to treatment with subsequent treatment cycles.” Private payers may, of course, have their own covered diagnoses and their own rules for the necessity for performing 86301. Bruce Pegg, BA, MA, CPC, CFPC, Managing Editor, AAPC 
