Guidelines for Coding and Billing Mohs Surgery
Mohs micrographic surgery (MMS) is a highly specialized procedure for treating skin cancer, especially basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). It involves the systematic removal of cancerous tissue layer by layer, followed by immediate microscopic examination to ensure all cancerous cells have been removed. Given its complexity and precision, proper coding and billing for Mohs surgery are essential for accurate reimbursement and compliance with Medicare and insurance guidelines.
This blog provides an overview of the key guidelines for coding and billing Mohs surgery.
CPT Codes for Mohs Surgery
The Current Procedural Terminology (CPT) code set defines specific codes for Mohs surgery based on the number of stages and tissue removed.
Primary CPT Codes for Mohs Surgery:
- 17311: Mohs micrographic surgery, face, ears, eyelids, nose, lips; first stage.
- 17312: Mohs micrographic surgery, face, ears, eyelids, nose, lips; each additional stage.
- 17313: Mohs micrographic surgery, other than face, ears, eyelids, nose, lips; first stage.
- 17314: Mohs micrographic surgery, other than face, ears, eyelids, nose, lips; each additional stage.
Explanation:
- 17311 and 17312 are used for Mohs surgery performed on the face, ears, eyelids, nose, and lips. These areas are more complex due to cosmetic concerns and anatomical features, which justify higher reimbursement.
- 17313 and 17314 are used for Mohs surgery performed on other body areas.
For multiple stages (i.e., when tissue is removed layer by layer), you will use the initial stage code for the first excision and the additional stage code for each subsequent stage of tissue removal.
Histopathologic Examination and Additional Services
The examination of tissue specimens is an integral part of the Mohs procedure, and it should be properly documented. Mohs surgery involves both excision and tissue processing, which may require separate coding:
- 88305: Level IV – Surgical pathology, gross and microscopic examination.
- 88307: Level V – Surgical pathology, gross and microscopic examination, typically for more complex specimens.
- 88304: Surgical pathology, gross examination only (used in rare cases where no microscopic examination is required).
If tissue is processed and examined by a separate entity, such as a pathologist’s office, these codes would be applied to the pathology report, which should be attached to the surgical record.
Pathology https://codingclarified.com/medical-coding-pathology/
Coding for the Reconstruction (Repair) Post-Surgery
After Mohs surgery, a reconstructive procedure may be needed, particularly on cosmetically sensitive areas like the face. These repair procedures are coded separately, based on the complexity of the repair and the anatomical site:
- 12001-12018: Simple repair codes based on the length of the wound.
- 13100-13153: Complex repair codes.
- 14000-14302: Flap or graft codes, which may be used when more extensive reconstructive work is required.
It is important to note that you cannot bundle the repair codes into the Mohs surgery codes. They should be billed separately, with the appropriate modifiers.
Modifiers
Modifiers are used to indicate specific circumstances related to the procedure. For Mohs surgery, these are particularly important to ensure accurate billing and reimbursement. Common modifiers used in Mohs surgery billing include:
- Modifier 59: Used to indicate that the excision and repair are distinct procedures. For example, when a larger excision or additional repair is performed during the same encounter.
- Modifier 51: Used when multiple procedures are performed during a single session but are unrelated to the primary procedure (e.g., when excision of multiple lesions is done in a single visit).
- Modifier 52: Used when a procedure is reduced in its scope or complexity, such as when a Mohs procedure is partially completed.
For example, if a separate repair is performed at a different site during the same surgical encounter, modifier 51 may be used. However, modifier 59 is critical to demonstrate that the repair is not part of the original Mohs excision but a separate procedure.
CPT Modifiers https://codingclarified.com/cpt-medical-modifiers/
Billing for Anesthesia
Anesthesia services related to Mohs surgery are typically billed separately. The anesthesia code used will depend on the complexity and duration of the procedure, and the anesthesia provider should document the time and type of service provided. Common anesthesia codes include:
- 00100-01999: General anesthesia codes. The specific code used will depend on the location and complexity of the surgery.
- 99100-99140: Used for anesthesia services provided in a facility or for patients with specific conditions requiring more intensive anesthesia management.
Other Considerations in Mohs Surgery Billing
- Documentation: Thorough documentation is essential for billing and coding Mohs surgery. This includes detailed records of the stages of surgery, the size of the excised tissue, pathology reports, and any additional procedures (such as repairs).
- Multiple Lesions: When performing Mohs surgery on multiple lesions, you must report each lesion separately, with the corresponding CPT codes for each stage. The coding should reflect the total number of stages performed.
- Unbundling: Be cautious with unbundling services, which is the practice of coding separately for components of a procedure that are generally included in the base code. This is often viewed as improper coding and can result in claim denials or audits.
Insurance Considerations
Each insurance payer may have specific guidelines for the coding and billing of Mohs surgery. It is crucial to verify the payer’s policies regarding:
- Coverage for Mohs Surgery: Ensure that the patient’s insurance covers Mohs surgery, especially for non-face lesions, which may have different reimbursement rates.
- Prior Authorization: Some insurers require prior authorization for Mohs surgery, especially for patients with non-melanoma skin cancer or those receiving multiple stages of surgery.
- Payment Rates: Payment rates can vary based on the site of the surgery (e.g., face vs. other body sites), and some payers may have special payment policies for high-complexity cases.
Common Billing Errors to Avoid
- Incorrect Stage Coding: Failing to report the number of stages correctly can result in underpayment. Ensure that each stage is reported properly and include the additional stage codes for each layer of excision.
- Under- or Over-Coding Repairs: The complexity of the repair should be documented, as incorrect coding (e.g., coding a complex repair as a simple one) can lead to issues with payment.
- Failing to Report Pathology Services: Omitting pathology services from the claim, such as the examination of the excised tissue, can result in incomplete billing and missing revenue.
Accurate coding and billing for Mohs surgery require a thorough understanding of the procedure, proper documentation, and knowledge of payer-specific guidelines. By adhering to the appropriate CPT codes, modifiers, and billing practices, medical providers can ensure they are reimbursed fairly and comply with regulations. Proper coding not only benefits the practice but also ensures that patients receive the necessary care without delay due to administrative errors. Always consult the latest CPT code updates and payer-specific guidelines to remain compliant and maximize reimbursement.
Billing and Coding: Mohs Micrographic Surgery (MMS)
https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleId=57767&ver=12