01-095 Mohs Surgery Notification of Medical Review

Noridian Healthcare Solutions, LLC, (Noridian) as the Supplemental Medical Review Contractor (SMRC) for the Centers for Medicare and Medicaid Services (CMS), is conducting post-payment coding review of claims for Medicare Part B Mohs Current Procedural Terminology (CPT) codes, 17312 and 17314, billed on dates of service (DOS) from January 1, 2022, through December 31, 2022. This notification includes the reasons for the review, documentation that will be requested in the Additional Documentation Request (ADR) letter, and resources providers/suppliers may wish to consult when submitting claims.


Mohs micrographic surgery (MMS) is a specialized, tissue-sparing procedure for the surgical removal of complex or ill-defined skin cancer. The Mohs technique involves the surgical excision of the visible tumor followed by excision of a thin layer of normal appearing tissue surrounding the tumor. The excised tissue is immediately processed in an on-site laboratory for microscopic examination to identify whether any cancer cells are present. If cancer cells are present, additional excision and tissue evaluation are repeated until the margins are clear of cancer cells.

The initial excision and microscopic evaluation, considered the first stage of the Mohs procedure, are assigned CPT codes 17311 (Removal and microscopic exam of growth of head, neck, hands, feet, or genitals, 1-5 tissue blocks) or 17313 (removal and microscopic exam of growth of trunk, arms, or legs, 1-5 tissue blocks) depending on the location of the tumor being excised. CPT 17315 (Removal and microscopic exam of growth, each additional block after 5 tissue blocks) is an add-on code utilized when additional tissue blocks are needed beyond the 1-5 tissue blocks in the first stage. Add on codes, CPT 17312 (Removal and microscopic exam of growth of head, neck, hands, feet, or genitals, each additional stage, 1-5 tissue blocks) and 17314 (Removal and microscopic exam of growth of trunk, arms, or legs, each additional stage, 1-5 tissue blocks) are billed when further excision is required for remaining cancer cells not cleared by the previous excision levels.

Reason for Review

The SMRC is tasked to perform data analysis and conduct a coding review for claims billed with the Mohs surgery add-on codes 17312 and 17314 with DOS January 1, 2022, through December 31, 2022.

The SMRC will conduct medical record reviews in accordance with applicable waivers/flexibilities/statutory, regulatory, and sub-regulatory guidance.

Claim Sample Detail

CPT Description
17312 Removal and microscopic exam of growth of head, neck, hands, feet, or genitals, each additional stage, 1-5 tissue blocks
17314 Removal and microscopic exam of growth of trunk, arms, or legs, each additional stage, 1-5 tissue blocks

Access related project details below.

Documentation Requirements

Below is a list of specific documentation requirements that will be included in each ADR to obtain the necessary documentation to perform the review.

Providers/suppliers are requested to submit each of the Documentation Requirements outlined below, if and as applicable to the claim on review.

  1. Operative/procedure report.
  2. Biopsy results must be included (Mohs tissue).
  3. Documentation to support the code(s) and modifier(s) billed.
  4. Signature log or signature attestation for any missing or illegible signatures within the medical record (all personnel providing services).
  5. Advance Beneficiary Notice of Non-Coverage (ABN)/Notice of Medicare Non-Coverage (NOMNC).
  6. Any other supporting/pertinent documentation.
  7. If medical record documentation is submitted via esMD: Beneficiary identification, date of service, and provider of the service should be clearly identified on each page of the submitted documentation.
  8. PLEASE NOTE: It is the responsibility of the supplier or provider to obtain all documentation from the ordering/referring provider to ensure medical necessity criteria have been met.


Social Security Act (SSA), Title XVIII

  • § 1815(a) Payment to Providers of Services
  • § 1833(e) Payment of Benefits
  • § 1861(s)(1) Physician Services
  • § 1861(s)(2) Services and Supplies
  • § 1861(s)(3) Medical and Other Health Services
  • § 1862(a)(1)(A) Exclusions from Coverage and Medicare as Secondary Payer
  • § 1879(a)(1) Limitation on Liability of Beneficiary where Medicare Claims are Disallowed
  • § 1893(b) Medicare Integrity Program

42 Code of Federal Regulations (CFR)

  • § 410.28 Hospital or CAH diagnostic services furnished to outpatients: Conditions
  • § 410.32(d)(2) Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions
  • § 410.64 Additional Preventative Services
  • § 411.15(k)(1) Any services that are not reasonable and necessary
  • § 424.5 Basic Conditions
  • § 493 Laboratory Regulations

Internet Only Manual (IOM), Medicare Benefit Policy Manual (MBPM), Publication (Pub.) 100-02

  • Chapter (Ch.) 6 § 20 Hospital Services Covered Under Part B
  • Ch. 15 § 30 Physician Services
  • Ch. 16 General Exclusion from Coverage

IOM, Medicare Claims Processing Manual (MCPM), Pub. 100-04

  • Ch. 1 General Billing Requirements
  • Ch. 12 § 20.3 Bundled Services/Supplies
  • Ch. 12 § 40-40.6 Surgeons and Global Surgery
  • Ch. 12 § 60 Payment for Pathology Services
  • Ch. 23 § 20.9 National Correct Coding initiative (NCCI)
  • Ch. 23 § Instructions for Codes with Modifiers (A/B MACs (B) Only)
  • Ch. 30 § 50.3 Financial Liability Protections

IOM, Medicare Program Integrity Manual (MPIM), Pub. 100-08

  • Ch. 3 Verifying Potential Errors and Taking Corrective Actions
  • Ch. 3 § Requested Records Not Received
  • Ch. 3 § Review Timelines Requirements
  • Ch. 3 § Signature requirements
  • Ch. 3 § Coding Determinations


  • Medicare National Correct Coding Initiative Policy Manual, Ch. 3 § F Mohs Micrographic Surgery Effective January 1, 2020, and January 1, 2021

Last Updated Jun 2, 2023