Neurosurgery Coding Alert

Question: What are 'M' codes? Should I use them?

California Subscriber

Answer: M codes (for example, M8000/0, Neoplasm, benign) are supplemental diagnosis codes (listed in Appendix A of ICD-9) that provide additional information in describing carcinoma and neoplasm morphology. Use of these codes allows for tracking of tumor histology and behavior, and can have advantages for hospital tumor registries or cancer centers.
 
From a reimbursement standpoint, you will gain no advantage by using M codes. You would never rely on an M code as a principle diagnosis, and unless you are specifically asked to use these codes by your payer or facility, you needn't worry about them.