Article - Billing and Coding: Mohs Micrographic Surgery (A56514)

CMS National Coverage PolicyTitle XVIII of the Social Security Act, Section 1862(a)(1)(A). This section allows coverage and payment for only those services that are considered to be medically reasonable and necessary.Title XVIII of the Social Security Act, Section 1833(e). This section prohibits Medicare payment for any claim which lacks the necessary information to process the claim.CMS Publications:CMS Publication 100-02,Medicare Benefit Policy Manual, Chapter 15, Section 30, Physician ServicesCMS Publication 100-02,Medicare Benefit Policy Manual, Chapter 16, Section 120, Cosmetic SurgeryCMS Publication 100-04,Medicare Claims Processing Manual, Chapter 12 Section 40-40.6, Surgeons and Global SurgeryCMS Publication 100-04,Medicare Claims Processing Manual, Chapter 12, Section 60, Payment for Pathology ServicesCMS Transmittal No. 434, Publication 100-04,Medicare Claims Processing Manual, Change Request #3458, January 14, 2005, Addition of CLIA Edits to Certain Health Care Procedure Coding System (HCPCS) Codes for Mohs Surgery.Article TextThe following coding and billing guidance is to be used with its associated Local Coverage Determination.As defined by the American Medical Association Current Procedural Terminology (American Medical Association, Chicago, IL), Mohs Micrographic Surgery (MMS) is a technique for the removal of complex or ill-defined skin cancer with histologic examination of 100% of the surgical margins. It is a combination of surgical excision and surgical pathology that requires a single physician to act in 2 integrated but separate and distinct capacities: surgeon and pathologist. The Mohs surgeon removes the tumor tissue and maps and divides the tumor specimen into pieces, and each piece is embedded into an individual tissue block for histopathologic (hematoxylin-eosin or toluidine blue) examination. Thus, a tissue block in MMS is defined as an individual tissue piece embedded in a mounting medium for sectioning.If a surgeon performs an excision using Mohs surgical techniques but does not personally provide the histologic evaluation of the specimen(s), the CPTcodes for MMS shall not be used. Instead standard excision codes should be chosen for such medically necessary services (e.g., 11600  11646).Medicare is aware that a biopsy of the skin lesion for which Mohs surgery is planned may be necessary for the physician to determine the exact nature of the lesion(s) to be removed. Occasionally, that biopsy may need to be done on the same day that the Mohs surgery is planned. To allow separate payment for a nonroutine histochemical stain on frozen tissue during Mohs surgery, report 88314 with modifier 59.If a prior biopsy of the site undergoing Mohs surgery has been previously performed within the last 60 days, the surgeon should make a reasonable effort to obtain those results rather than repeating the biopsy.Reporting both Mohs Micrographic Surgery CPTcodes 17311-17315 and Surgical Pathology CPT88302-88309 or 88331-88332, on tissue used for margin evaluation during Mohs surgery is inappropriate and will indicate that true Mohs surgery was not done. Such claims for Mohs surgery (17311-17315) will be denied. There are occasional clinical situations in which tissue separate from the tissue examined during Mohs surgery is appropriately submitted for subsequent formalin fixed processing and histopathologic examination. The submitted tissue is not the same tissue that was processed during the Mohs surgery. It may constitute a tissue margin beyond that evaluated with Mohs surgery or it may involve a totally unrelated tissue specimen. In such situations both the Mohs surgery and the histopathology are subject to coverage. In such cases the clinical record must clearly show the reasoning for the histopathologic specimen and interpretation. To allow separate payment for a biopsy and pathology on a separate skin lesion, other than the lesion for which Mohs surgery is performed on the same day, the -59 modifier is appropriate.If reporting the -59 modifier with a skin biopsy/pathology code on the same day the Mohs surgery was performed, the physician's documentation should clearly indicate:That the biopsy was performed on a lesion other than the one on which Mohs surgery was performed;If the biopsy is of the same lesion as the Mohs lesion, that a biopsy of that lesion had not been done within the previous 60 days; orIf there has been a recent (within 60 days) biopsy of the same lesion as the Mohs lesion, the results of that biopsy were unobtainable despite reasonable effort by the Mohs surgeon.Documentation requirementsThe majority of simple skin cancers can be managed by simple excision or destruction techniques. The medical records should clearly show that Mohs surgery was chosen because of the complexity, size and/or location of the lesion and why other approaches are not medically necessary and reasonable.The operative notes and pathology documentation in the patient's medical record must clearly show that Mohs micrographic surgery was performed using accepted Mohs technique, with the same physician performing both the surgical and pathology services. The notes should also contain the location, number and size of the lesion(s), the number of stages performed, and the number of specimens per stage.Documentation must be available to Medicare contractors upon request.The Mohs surgeon must describe the histology of the specimens taken in the first stage. That description should include depth of invasion, pathological pattern, cell morphology, and, if present, perineural invasion or presence of scar tissue. For subsequent stages, you may note that the pattern and morphology of the tumor (if still seen) is as described for the first stage; or, if differences are found, note the changes. There is no need to repeat the detailed description documented for the first stage, presuming that the description would fit the tumor found on subsequent stages.The patient's medical record must contain documentation that fully supports the medical necessity for services included within this LCD in accordance with this LCD. This documentation should include, but is not limited to, relevant medical history, physical examination, and results of pertinent diagnostic tests or procedures including biopsy reports along with the procedural note.Sources:American Medical Association. Mohs Micrographic Surgery. CPT Assistant 2006;16:1-7