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Official Description

Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (eg, hematoxylin and eosin, toluidine blue), of the trunk, arms, or legs; first stage, up to 5 tissue blocks

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Common Language Description

The Mohs micrographic surgery technique, represented by CPT® Code 17313, is a specialized surgical method designed for the precise removal of complex or ill-defined skin cancers. This technique is particularly effective for treating basal cell carcinoma and squamous cell carcinoma, which are among the most prevalent forms of skin cancer. In this procedure, the physician assumes dual roles as both the surgeon and the pathologist, allowing for immediate examination of the excised tissue. The process involves the meticulous removal of the tumor in thin layers, which are then subjected to microscopic examination. This immediate analysis is crucial as it enables the surgeon to confirm the complete removal of cancerous cells while preserving as much healthy tissue as possible. The Mohs technique is characterized by its high success rate in cancer removal, attributed to the detailed mapping and color coding of the excised specimens. Each layer of tissue removed is carefully stained, often using routine stains such as hematoxylin and eosin or toluidine blue, to facilitate the identification of any remaining cancer cells. This systematic approach ensures that the surgeon can accurately track the tumor's extent and ensure complete excision. The specific code 17313 applies to the first stage of this procedure when up to five tissue blocks are removed from the trunk, arms, or legs. Subsequent stages and additional tissue blocks are coded separately, allowing for comprehensive documentation and billing of the entire surgical process.

© Copyright 2025 Coding Ahead. All rights reserved.

1. Indications

The Mohs micrographic surgery technique is indicated for the treatment of specific types of skin cancer, particularly when the tumors are complex or ill-defined. The following conditions warrant the use of this procedure:

  • Basal Cell Carcinoma - A common form of skin cancer that arises from the basal cells in the epidermis, often characterized by slow growth and a tendency to invade surrounding tissues.
  • Squamous Cell Carcinoma - Another prevalent skin cancer that originates from squamous cells, which are flat cells located in the outer layer of the skin. This type of cancer can be more aggressive than basal cell carcinoma and may metastasize if not treated promptly.

2. Procedure

The Mohs micrographic surgery procedure involves several critical steps to ensure the effective removal of cancerous tissue while preserving healthy skin. The following outlines the procedural steps:

  • Initial Tumor Excision - The surgeon begins by excising the visible tumor along with a margin of surrounding healthy tissue. This initial removal is performed in thin layers to facilitate accurate examination of the tissue.
  • Mapping and Color Coding - After the initial excision, the removed tissue specimens are meticulously mapped and color-coded. This process allows the surgeon to keep track of the specific areas from which the tissue was taken, ensuring precise identification of any remaining cancerous cells during subsequent examinations.
  • Microscopic Examination - The excised tissue is then subjected to immediate microscopic examination by the surgeon. This step is crucial as it allows for the rapid assessment of whether cancerous cells remain in the margins of the excised tissue.
  • Histopathologic Preparation - The specimens undergo histopathologic preparation, which includes routine staining techniques such as hematoxylin and eosin or toluidine blue. This preparation enhances the visibility of cellular structures, aiding in the identification of cancerous cells.
  • Additional Stages as Needed - If cancerous cells are detected in the margins during the microscopic examination, the surgeon will proceed with additional stages of excision, repeating the mapping, color coding, and examination process until clear margins are achieved.

3. Post-Procedure

Post-procedure care following Mohs micrographic surgery is essential for optimal recovery and monitoring. Patients may experience some swelling, redness, or discomfort at the surgical site, which is typically managed with standard pain relief measures. It is important for patients to follow the surgeon's instructions regarding wound care, which may include keeping the area clean and dry, applying prescribed topical medications, and avoiding sun exposure to promote healing. Follow-up appointments are crucial to assess the surgical site for any signs of infection or complications and to ensure that the cancer has been completely removed. The surgeon will also discuss any further treatment options if necessary, based on the pathology results obtained from the excised tissue.

Short Descr MOHS 1 STAGE T/A/L
Medium Descr MOHS TRUNK/ARM/LEG 1ST STAGE 5 BLOCKS
Long Descr Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (eg, hematoxylin and eosin, toluidine blue), of the trunk, arms, or legs; first stage, up to 5 tissue blocks
Status Code Active Code
Global Days 000 - Endoscopic or Minor Procedure
PC/TC Indicator (26, TC) 0 - Physician Service Code
Multiple Procedures (51) 2 - Standard payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 1 - Statutory payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Procedure or Service, Multiple Reduction Applies
ASC Payment Indicator Office-based surgical procedure added to ASC list in CY 2008 or later with MPFS nonfacility PE RVUs; payment based on OPPS relative payment weight.
Type of Service (TOS) 2 - Surgery
Berenson-Eggers TOS (BETOS) P5A - Ambulatory procedures - skin
MUE 3
CCS Clinical Classification 170 - Excision of skin lesion

This is a primary code that can be used with these additional add-on codes.

17314 Addon Code MPFS Status: Active Code APC N ASC N1 CPT Assistant Article Illustration for Code Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (eg, hematoxylin and eosin, toluidine blue), of the trunk, arms, or legs; each additional stage after the first stage, up to 5 tissue blocks (List separately in addition to code for primary procedure)
17315 Addon Code MPFS Status: Active Code APC N ASC N1 CPT Assistant Article Illustration for Code Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (eg, hematoxylin and eosin, toluidine blue), each additional block after the first 5 tissue blocks, any stage (List separately in addition to code for primary procedure)
88311 Addon Code MPFS Status: Active Code APC N PUB 100 CPT Assistant Article Decalcification procedure (List separately in addition to code for surgical pathology examination)
88314 Addon Code MPFS Status: Active Code APC N PUB 100 CPT Assistant Article Special stain including interpretation and report; histochemical stain on frozen tissue block (List separately in addition to code for primary procedure)
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
GC This service has been performed in part by a resident under the direction of a teaching physician
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
58 Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78.
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
GW Service not related to the hospice patient's terminal condition
RT Right side (used to identify procedures performed on the right side of the body)
LT Left side (used to identify procedures performed on the left side of the body)
SG Ambulatory surgical center (asc) facility service
53 Discontinued procedure: under certain circumstances, the physician or other qualified health care professional may elect to terminate a surgical or diagnostic procedure. due to extenuating circumstances or those that threaten the well being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued. this circumstance may be reported by adding modifier 53 to the code reported by the individual for the discontinued procedure. note: this modifier is not used to report the elective cancellation of a procedure prior to the patient's anesthesia induction and/or surgical preparation in the operating suite. for outpatient hospital/ambulatory surgery center (asc) reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
78 Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period: it may be necessary to indicate that another procedure was performed during the postoperative period of the initial procedure (unplanned procedure following initial procedure). when this procedure is related to the first, and requires the use of an operating/procedure room, it may be reported by adding modifier 78 to the related procedure. (for repeat procedures, see modifier 76.)
AG Primary physician
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
CR Catastrophe/disaster related
GA Waiver of liability statement issued as required by payer policy, individual case
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GZ Item or service expected to be denied as not reasonable and necessary
KX Requirements specified in the medical policy have been met
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
Q5 Service furnished under a reciprocal billing arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
SA Nurse practitioner rendering service in collaboration with a physician
X2 Continuous/focused services: for reporting services by clinicians whose expertise is needed for the ongoing management of a chronic disease or a condition that needs to be managed and followed with no planned endpoint to the relationship; reporting clinician service examples include but are not limited to: a rheumatologist taking care of the patient's rheumatoid arthritis longitudinally but not providing general primary care services
X4 Episodic/focused services: for reporting services by clinicians who provide focused care on particular types of treatment limited to a defined period and circumstance; the patient has a problem, acute or chronic, that will be treated with surgery, radiation, or some other type of generally time-limited intervention; reporting clinician service examples include but are not limited to, the orthopedic surgeon performing a knee replacement and seeing the patient through the postoperative period
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
XP Separate practitioner, a service that is distinct because it was performed by a different practitioner
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
Action
Notes
2011-01-01 Changed Short description changed.
2007-01-01 Added First appearance in code book in 2007.
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