Lab: Special Histochemical Stains and Immunohistochemical Stains
L36353
Medicare covers special histochemical and immunohistochemical stains when a pathologist documents that the additional testing is medically necessary to produce a complete, accurate diagnosis used by the treating physician and when results will affect patient management. Reflex or pre-ordered stains prior to H&E review, routine/staged ordering of stains on all specimens, chemosensitivity panels, and tests that do not provide actionable information (including most Ki-67 testing for breast cancer outside a specific abemaciclib-related scenario) are not covered. Pathology reports must document block designation, reasons, markers used, results, and communication to the treating clinician; specific clinical justifications are required for many organ-specific uses (e.g., GI, prostate, renal, lung, bone marrow).
"Special histochemical and immunohistochemical (IHC) stains are medically necessary when required to achieve a complete and accurate diagnosis reported to and used by the treating physician, and the..."