By Glenn Goldman, MD
Mohs micrographic surgery is facing scrutiny due to increased utilization. The use of Mohs surgery is increasing more rapidly than is the incidence of skin cancer, and this is an area of concern for payers. The value of Mohs surgery in treating skin cancer, reimbursement for the procedure, and our continued ability to perform Mohs surgery are, in a manner of speaking, under the microscope.
Changes in the rules for in-office ancillary services, driven by rising utilization of dermatopathology codes, could put Mohs surgery into a regulatory gray zone. However, as dermatologists, we can affect change in this area by making sure we are using Mohs surgery only when it’s appropriate. Some lesions treated using Mohs surgery may be treated effectively with other means.
Focus on trunk and extremities
Not only has the utilization of Mohs surgery risen in recent years, but utilization for CPT code 17313, for Mohs performed on the trunk and extremities, has increased more than 10 percent in the past two years. Most Mohs surgery is performed on the head and neck, but there is concern from payers that smaller tumors on the trunk and extremities could be treated with less-expensive and equally effective modalities.
Medicare will consider reimbursement for Mohs surgery for accepted diagnoses and indications. The current accepted diagnoses and indications are listed in your Medicare Local Coverage Determination (LCD). Mohs surgery indications on the trunk and extremities include aggressive histology; large size; location on the shin, hand, foot, or digits; perineural invasion; positive margins on prior excision; and immunosuppression.
The importance of documentation
The Mohs surgeon must clearly and appropriately document in the patient medical record to indicate that the diagnosis is appropriate for Mohs surgery. Documentation must clearly show that Mohs surgery was chosen because of the complexity (e.g., prior treatment), size, or location (e.g., location in the H-zone of the face, shin, hand, etc.), and that Mohs surgery was the most appropriate choice for treatment of a particular lesion.
Medicare has published MLN SE1318, “Guidance to Reduce Mohs Surgery Reimbursement Issues,” to provide further clarification.
Noridian Administrative Services (NAS), which represents Jurisdiction E (WA, OR, MT, ID, WY, ND, SD, UT, AZ, AK) and F (CA, NV, HI, AS, MP, GU) has adopted the indication from MLN SE1318 as part of the clinical documentation requirements for Mohs surgery. They state, “The 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, the surgeon 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.”
See "Cracking the Code: Mohs Clinical Documentation" for an overview of MLN SE1318.
Note: Mohs surgeons in other regions should check their local Medicare carrier LCD to see if and when these changes will be applied to your LCDs.
The following are examples of appropriate use and non-use of Mohs surgery: