Neurology & Pain Management Coding Alert

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

California Subscriber

Answer: The 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 (that is, the cellular nature of tumors). Hospital tumor registries or cancer centers find these codes useful for tracking tumor histology and behavior.
 
M codes will not gain you a reimbursement advantage, and payers normally do not require them. Never rely on an M code as a principle diagnosis. Unless you are specifically asked to use these codes by your payer or facility, you needn't worry about them.