Two new Medicare Local Coverage Determinations (LCDs) define medical necessity requirements for the use of special stains and immunohistochemical (IHC) stains. They are in effect for Palmetto GBA and Wisconsin Physicians Service (WPS) for services performed on or after July 14, 2024.
Palmetto GBA (L35922) is the Medicare Administrative Contractor (MAC) for the states of Alabama, Georgia, North Carolina, South Carolina, Tennessee, Virginia and West Virginia.
The Wisconsin Physicians Service (WPS) jurisdiction includes the states of Indiana, Iowa, Kansas, Michigan, Missouri and Nebraska for the LCD (L36805).
Medical Necessity Requirements
Guidance published by the Centers for Medicare and Medicaid Services (CMS) states the pathologist may perform such additional tests for Medicare or Medicare Advantage patients under the following circumstances:
- Services are medically necessary so that a complete and accurate diagnosis can be reported to the treating physician/practitioner.
- Results of the tests are communicated to and are used by the treating physician/practitioner in the treatment of the beneficiary.
- Pathologist documents in their report why additional testing was done.
CMS notes in general the pathologist must first review the routing hematoxylin and eosin (H&E) stain but also states exceptions do exist so providers are encouraged to review the specimen-specific sections of the applicable LCD for more information.
In addition, the guidance states, “The surgical pathology report is expected to designate the specific block(s) upon which IHC testing is performed, the reason and results for IHC testing, the specific markers, and whether single antibody(s) or a cocktail of antibodies is utilized.” It also cautions, “A statement alone in the pathology report that states, ‘IHC confirms the diagnosis’ will not be covered as reasonable and necessary.”
Failure to support medical necessity
CMS provides examples of scenarios they feel may drive overutilization or incorrect billing of medically unnecessary services, including:
- Reflex templates or pre-orders for special stains and/or IHC stains prior to review of the routine hematoxylin and eosin (H&E) stain by the pathologist; or
- Use of special stains and/or IHC stains without clinical evidence that the stain is actionable or provides the treating physician with information that changes patient management; or
- Use of added stains when the diagnosis is already known based on morphologic evaluation of the primary stain.
CMS guidance also notes “Exceptions do exist and are recognized standards of care in the practice of pathology. These exceptions include, but are not limited to, renal, liver and neuromuscular biopsies, and for the suspicion of an infectious disease, particularly in an immune-compromised patient. In certain clearly defined circumstances, it may be reasonable to perform some IHC on sentinel lymph nodes when the frozen section show they are free of tumor.”
What’s Next?
Liz Hansard, CPC, COC, Vice President of Pathology for MSN Healthcare Solutions, states, “LCDs approved by a Medicare Administrative Contractor are often adopted by other MACs as well as by commercial insurance plans. We will continue to monitor activity and report any updates but also encourage practices to watch for local and plan-specific changes.”
