Billing and Coding: Mohs Micrographic Surgery

This article gives guidance for billing, coding, and other guidelines in relation to local coverage policy L34195 Mohs Micrographic Surgery. General Guidelines for Claims submitted to Part A or Part B MAC: Procedure codes may be subject to National Correct Coding Initiative (NCCI) edits or OPPS packaging edits. Refer to NCCI and OPPS requirements prior to billing Medicare. For services requiring a referring/ordering physician, the name and NPI of the referring/ordering physician must be reported on the claim. A claim submitted without a valid ICD-10-CM diagnosis code will be returned to the provider as an incomplete claim under Section 1833(e) of the Social Security Act. The diagnosis code(s) must best describe the patient's condition for which the service was performed. For diagnostic tests, report the result of the test if known; otherwise the symptoms prompting the performance of the test should be reported. Advance Beneficiary Notice of Non-coverage (ABN) Modifier Guidelines An ABN may be used for services which are likely to be non-covered, whether for medical necessity or for other reasons. Refer to CMS Publication 100-04, Medicare Claims Processing Manual, Chapter 30, for complete instructions. Effective from April 1, 2010, non-covered services should be billed with modifier –GA, -GX, -GY, or –GZ, as appropriate. The –GA modifier (“Waiver of Liability Statement Issued as Required by Payer Policy”) should be used when physicians, practitioners, or suppliers want to indicate that they anticipate that Medicare will deny a specific service as not reasonable and necessary and they do have an ABN signed by the beneficiary on file. Modifier GA applies only when services will be denied under reasonable and necessary provisions, sections 1862(a)(1), 1862(a)(9), 1879(e), or 1879(g) of the Social Security Act. Effective April 1, 2010, Part A MAC systems will automatically deny services billed with modifier GA. An ABN, Form CMS-R-131, should be signed by the beneficiary to indicate that ‎he/she accepts responsibility for payment.‎ The -GA modifier may also be used on assigned claims when a patient refuses to sign the ABN and the latter is properly witnessed. For claims submitted to the Part A MAC, occurrence code 32 and the date of the ABN is required. Modifier GX (“Notice of Liability Issued, Voluntary Under Payer Policy”) should be used when the beneficiary has signed an ABN, and a denial is anticipated based on provisions other than medical necessity, such as statutory exclusions of coverage or technical issues. An ABN is not required for these denials, but if non-covered services are reported with modifier GX, will automatically be denied services. The –GZ modifier should be used when physicians, practitioners, or suppliers want to indicate that they expect that Medicare will deny an item or service as not reasonable and necessary and they have not had an ABN signed by the beneficiary. ‎If the service is statutorily non-covered, or without a benefit category, submit the ‎appropriate CPT/HCPCS code with the -GY modifier. An ABN is not required for these denials, and the limitation of liability does not apply for beneficiaries. Services with modifier GY will automatically deny. Documentation Requirements The patient’s medical record should include but is not limited to: The assessment of the patient by the ordering provider as it relates to the complaint of the patient for that visit, Relevant medical history Results of pertinent tests/procedures Signed and dated office visit record/operative report (Please note that all services ordered or rendered to Medicare beneficiaries must be signed.) For claims submitted to the Part A MAC: This coverage determination also applies within states outside the primary geographic jurisdiction with facilities that have nominated CGS Administrators, LLC to process their claims. The patient's medical record must contain documentation that fully supports the medical necessity for services included within this LCD. When billing for MOHS on the trunk or extremities, please insert one or more of the qualifying terms in the notepad of the electronic claim. (See "Indications and Limitations of Coverage.") This documentation includes, but is not limited to, relevant medical history, physical examination, and results of pertinent diagnostic tests or procedures. The majority of 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. 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 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. 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; or if 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.