**Coverage Indications, Limitations, and/or Medical Necessity**  
  
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. If either of these
responsibilities is delegated to another physician who reports the services
separately, these codes should not be reported. 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. (American Medical Association. Mohs Micrographic Surgery. CPT
Assistant 2006;16:1-7)  
  
Mohs micrographic surgery is a two-step process: the tumor is removed in
stages, followed by immediate histologic evaluation of the margins of the
specimen(s). Further excision is performed until all margins are clear. The
physician performing MMS furnishes both the surgical and pathological
services, i.e., the excision and the histologic evaluation of the specimen(s).  
  
**Mohs surgery is usually an outpatient procedure done under local anesthesia
(with or without sedation).**  
  
The majority of simple skin cancers can be managed by simple excision or
destruction techniques. The medical records should clearly document that Mohs
surgery was chosen because of the complexity (e.g. poorly defined clinical
borders, possible deep invasion, prior irradiation), size or location (e.g.
maximum conservation of tumor-free tissue is important).  
  
 **Indications:**  
After careful review Medicare Jurisdictions E and F have adopted coverage for
Mohs Micrographic Surgery in accordance with the 2012 Appropriate Use Criteria
(AUC) for Mohs Micrographic Surgery as published in the Journal of the
American Academy of Dermatology Volume 67, Issue 4, pp 531-550, October 2012.
These criteria were compiled based on collaboration of the American Academy of
Dermatology, the American College of Mohs Surgery, the American Society of
Dermatologic Surgery Association and the American Society for Mohs surgery
based on evidence based medicine, clinical practice experience and expert
judgment.  
  
Clinical settings that are supported by the criteria as denoted by the CPT
codes and ICD-10-CM codes listed in the Billing and Coding Article will be
considered for coverage when properly performed and the indications, procedure
and findings/results clearly and legibly documented within the beneficiary's
clinical record. Clinical settings noted to be inappropriate by the criteria
and not otherwise covered in this LCD will be denied and should NOT be billed
to Medicare as MMS.  
  
 _The majority of simple skin cancers can be managed by simple excision or
destruction techniques._ The medical records should clearly show that MMS was
chosen because of the complexity (e.g. poorly defined clinical borders,
possible deep invasion, prior irradiation), size or location (e.g. maximum
conservation of tumor-free tissue is important).  
  
 **Definitions:**

1\. **Area H:** Mask areas of the face (central face, eyelids [including
inner/outer canthi], eyebrows, nose, lips [cutaneous/mucosal/vermillion],
chin, ear and periauricular skin/sulci, temple), genitalia (including perineal
and perianal areas), hands, feet, nail units, ankles, nipples/areola.

2\. **Area M:** Cheeks, forehead, scalp, neck, jawline, pretibial surface.

3\. **Area L:** Trunk and extremities (excluding pretibial surfaces, hands,
feet, nail units and ankles).

4\. **Immunocompromised:** a patient with HIV/AIDS, organ transplant,
hematologic malignancy or pharmacologic suppression.

5\. **Genetic Syndromes:** basal cell nevus syndrome, xeroderma pigmentosa, or
other syndromes at high risk for skin cancer.

6\. **Healthy:** no immunosuppression, no prior radiation therapy to affected
area, no chronic infections and no genetic syndromes that predispose to skin
cancer.

7\. **Prior Radiated Skin:** patient has previously received therapeutic
radiation in this area of the body.

8\. **Aggressive features:**

a. For Basal Cell Carcinoma

i. Morpheaform, fibrosing, sclerosin

ii. Infiltrating

iii. Perineura iv. Metatypical/keratoti v. Micronodular

 b. For Squamous Cell Carcinoma

i. Sclerosing

ii. Basosquamous excluding keratotic BCC

iii. Small cell

iv. Poorly or undifferentiated, i.e. high degree of polymorphism, high mitotic
rate and/or low degree of keratinization

v. Perineural or perivascular

vi. Spindle cell

vii. Pagetoid

viii. Infiltrating

ix. Keratoacanthoma (KA) type: central facial

x. Single Cell

xi. Clear Cell

xii. Lymphoepithelial

xiii. Sarcomatoid

xiv. Breslow depth below 2mm or greater

xv. Clark level IV or greater

9\. **Tissue Block:**

A block is the plate that tissue is placed upon, coated with embedding medium,
frozen, and then placed into the microtome for cutting. Thus, a block is a
plate with tissue and mounting medium on it. How many tissue pieces go onto
the plate (block) does not matter. The technician, with possible input from
the physician, decides how many tissue pieces from a given excision stage
would fit on one tissue plate (block). For example, a specimen may be
butterflied and put on one block (tissue plate), or the same specimen could be
bisected and both tissue pieces put on one plate (block). It is still one
block. Another example: one may take a subsequent Mohs excision stage as three
separate, non-contiguous pieces (specimens). Each of the tissue pieces is
considered as a separate tissue specimen; however, depending upon their size
and the technician's proficiency, all three pieces could be placed upon one
plate (one block), or two pieces on one plate and one on another plate (2
blocks), or each of the three tissue pieces (specimens) could be placed on
individual plates (3 blocks). The block is the billing unit, not the tissue
piece.

**Indications:**  
Medicare will consider reimbursement for MMS for the following indications and
anatomic locations:  
  
I. _**Basal Cell Carcinom**_

_A. Recurrent BCC of any size or unexpected positive margin on recent excision
(healthy or immunocompromised or genetic syndrome(s))_

i. Aggressive Pathology  
1\. Area H, M, and/or L  
ii. Nodular pathology  
1\. Area H, M, and/or L  
iii. Superficial pathology  
1\. Area H and M only  
2\. No coverage for Area L  
  
B. _Primary Aggressive_  
i. Size  0.5 cm  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
ii. Size  0.6 cm  
1\. Area H, M, and L  
  
C. _Primary Nodular BCC (Healthy patient)_  
i. Size  0.5 - 1 cm  
1\. Area H and M only  
2\. No coverage for Area L  
ii. Size 1.1 - 2 cm  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
iii. Size  2  
1\. Area H, M, and L  
  
D. _Primary Nodular BCC (Immunocompromised patient)_  
i. Size  0.5 cm  
1\. Area H and M only  
2\. No coverage for Area L.  
ii. Size 0.6 - 1 cm  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
iii. Size  2 cm  
1\. Area H, M, and L  
  
E. _Primary Superficial BCC (Healthy Patient)_  
i. Size  0.5 cm  
1\. Area H.  
2\. Area M may be considered for coverage on redetermination.  
3\. No coverage for Area L.  
ii. Size  0.6 cm  
1\. Area H and M.  
2\. No coverage for Area L.  
  
F. _Primary Superficial BCC (Immunocompromised Patient)_  
i. Size  1.0 cm  
1\. Area H and M.  
2\. No coverage for Area L.  
ii. Size > 1.0 cm  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
  
II. **_Squamous Cell Carcinoma_**  
A. Recurrent SCC of any size or unexpected positive margin on recent excision  
i. Aggressive Pathology  
1\. Area H, M, and L  
ii. Verrucous Pathology  
1\. Area H  
iii. KA-type SCC (Not central facial)  
1\. Area H , M, and L  
iv. In situ/Bowen  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
v. AK with focal SCC in situ; Bowenoid AK; SCC in situ, AK type  
1\. NOT Covered  
vi. Without aggressive histologic features, < 2 mm depth without other
defining features, Clark level  III  
1\. Area H, M, and L  
  
B. _Primary aggressive SCC (healthy patients)_  
i. Size - all  
1\. Area H, M, and L  
  
C. _Primary aggressive SCC (Immunocompromised Patients)_  
i. Size - all  
1\. Area H, M, and L  
  
D. _Primary SCC Without aggressive histologic features, < 2 mm depth without
other defining features, Clark level  III (healthy patients)_  
i. Size  1.0 cm  
1\. Area H and M.  
2\. No coverage for Area L  
ii. Size 1.1 - 2 cm  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
iii. Size > 2 cm  
1\. Area H, M, and L  
  
E. _Primary SCC Without aggressive histologic features, < 2 mm depth without
other defining features, Clark level  III (Immunocompromised patients)_  
i. Size  1.0 cm  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
ii. Size  1.1 cm  
1\. Area H, M, and L  
  
F. _Primary verrucous SCC (healthy or immunocompromised patients)_  
i. All Sizes  
1\. Area H only  
2\. No Coverage for areas M and L as such tumors in these areas are extremely
rare. The rare occurrence may be covered on redetermination.  
  
G. _Primary SCC KA type, not central facial (healthy patients)_  
i. Size  1.0 cm  
1\. Area H and M.  
2\. No coverage for Area L  
ii. Size  1.1 cm  
1\. Area H, M, and L  
  
H. _Primary SCC KA type, not central facial (Immunocompromised patients)_  
i. Size  0.5 cm  
1\. Area H and M. Area L may be covered on redetermination  
ii. Size  0.6 cm  
1\. Area H, M, and L.  
  
I. _Primary in situ SCC/Bowen disease (healthy patients)_  
i. Size  1.0 cm  
1\. Area H and M.  
2\. No coverage for Area L  
ii. Size 1.1 - 2 cm  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
iii. Size > 2 cm  
1\. Area H, M, and L  
  
J. _Primary in situ SCC/Bowen disease (Immunocompromised patients)_  
i. Size  0.5 cm  
1\. Area H and M.  
2\. No coverage for Area L  
ii. Size 0.6 - 1 cm  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
iii. Size  1.1 cm  
1\. Area H, M, and L  
  
K. _Primary AK with focal SCC in situ; Bowenoid AK; SCC in situ, AK type
(healthy or immunocompromised patients)_  
i. Any size  
1\. Not covered  
  
III. **_Basal or Squamous Cell Carcinoma_**  
A. Primary BCC or SCC regardless of sub-type, size or depth arising in:  
i. Prior irradiated skin;  
ii. Traumatic scar;  
iii. Area of Osteomyelitis;  
iv. Area of chronic inflammation/ulceration, or  
v. Patients with genetic syndromes predisposing to skin cancer  
1\. Area H, M, and L  
  
IV. _**Lentigo Maligna and melanoma in situ**  
A. Primary lentigo maligna (healthy or immunocompromised patients)_  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
  
B. _Locally recurrent lentigo maligna (healthy or immunocompromised patients)_  
1\. Area H, M, and L  
  
C. _Primary melanoma in situ; non-lentigo maligna (healthy or
immunocompromised patients)_  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
  
D. _Locally recurrent melanoma in situ; non-lentigo maligna (healthy or
immunocompromised patients)_  
1\. Area H, M, and L  
  
V. **_Other less common skin cancers_**  
A. Adenocystic carcinoma  
1\. Area H, M, and L  
  
B. _Adnexal carcinoma_  
1\. Area H, M, and L  
  
C. _Apocrine/eccrine carcinoma_  
1\. Area H, M, and L  
  
D. _Angiosarcoma_  
1\. Area H, M, and L subject to records review for medical necessity.  
  
E. _Atypical fibroxanthoma_  
1\. Area H, M, and L  
  
F. _Bowenoid papulosis_  
1\. Not covered  
  
G. _Dermatofibrosarcoma protuberans_  
1\. Area H, M, and L  
  
H. _Desmoplastic trichoepithelioma_  
1\. Area H and M subject to medical records review for medical necessity.  
2\. Area L not covered  
  
I. _Extramammary Paget Disease_  
1\. Area H, M, and L  
  
J. _Leiomyosarcoma_  
1\. Area H, M, and L  
  
K. _Malignant fibrous histiocytoma_  
1\. Area H, M, and L  
  
L. _Merkel Cell Carcinoma_  
1\. Area H and M.  
2\. Area L may be covered on redetermination  
  
M. _Microcystic Adnexal Carcinoma_  
1\. Area H, M, and L  
  
N. _Mucinous Carcinoma_  
1\. Area H, M, and L  
  
O. _Sebaceous Carcinoma_  
1\. Area H, M, and L  
  
P. _Rare Biopsy proven malignancies not otherwise specified_  
1\. Area H, M, and L will be looked at for medical necessity on a pre-pay
basis or may be covered on redetermination.  
  
 **Limitations:**  
Only physicians (MD/DO) may perform Mohs micrographic surgery. (See Sections
1861 [s] [2] and 1862 [a] [140 of Title XVIII of the Social Security Act; 42
CFR, Sections 410.74, 410.75, 410.76 and 419.22; 58 FR 18543, April 7, 2000.)  
  
The physician (MD/DO) performing Mohs micrographic surgery must be
specifically trained and highly skilled in MMS techniques and pathologic
identification.