Mohs Dermatology Scribe: Defend Modifier 25 E/M

Why Modifier 25 Unravels in Mohs Charts

Most Mohs Modifier 25 denials do not begin with a coding error. They begin in the chart, where a full-body skin examination, a transplant-related risk discussion, and three stages of margin mapping are written as one continuous procedural narrative. When an auditor reads that note, the evaluation work looks like the routine preoperative assessment already bundled into the 0-day global of CPT 17311.

The standard is plain enough. Modifier 25 requires an E/M service that is significant and separately identifiable from the procedure performed on the same date. The decision to proceed with Mohs on a biopsy-proven lesion is not, by itself, that service. A total body skin exam that finds a new pigmented lesion on the back, a discussion with the transplant team about immunosuppression reduction, or a reset of surveillance intervals for a patient with a fourth squamous cell carcinoma this year can be.

Our view is simple. If the documentation does not separate these streams, the coder cannot defend them. Merry AI was built around that separation.

Splitting the Encounter Into Defensible Fields

The ambient engine listens once but writes in several places. As the surgeon examines, counsels, and operates, each transcript segment is tagged with a destination: full-body exam, immunosuppression risk, surveillance plan, or Mohs stage narrative. Nothing is merged for convenience. Each segment waits for clinician review before it reaches the chart.

Full-Body Exam and Skin Cancer Risk

Total body skin examination findings are written to the exam section of the visit note, not the procedure template. That includes regions examined, lesions of concern with location and morphology, dermoscopic impressions, and any biopsies ordered on separate lesions. When a patient mentions a lung transplant and current mycophenolate, the engine records it as a discrete immunosuppression entry rather than a phrase buried in the history. Gorlin syndrome, prior radiation at the site, and a history of multiple nonmelanoma skin cancers are handled the same way.

Mohs Stage and Margin Notes

Stage-level documentation stays inside the procedure note. The engine enriches the narrative summary field with the indication for Mohs, H-zone location, preoperative size, histologic subtype, number of stages, blocks per stage, and margin status at each stage. It does not overwrite the structured stage grid the surgeon maintains. Perineural invasion, infiltrative or micronodular patterns, and the reconstruction method are captured in the surgeon's own words, ready for attestation.

Chrome Overlay Field Mapping

Our Chrome Extension maintains a versioned field map for each supported browser-based EHR. The E/M sections and the procedure note are mapped as separate targets, even when the Mohs template lives in a nested iframe or a separate tab. A tab-context check confirms the active patient, the active encounter, and whether the field has been edited since the last write. No API contract or interface engine is required.

The Mohs Clinical Logic Matrix

Each diagnostic metric below corresponds to a data point the engine extracts and a billing argument it supports. Coders can read the matrix against current descriptor language at https://www.ama-assn.org/practice-management/cpt.

The matrix matters most when a single patient generates several claims on one date. Distinct sites and distinct lesions must remain distinct in the note, or NCCI edits will collapse them. Specialty prompt packs that mirror these rows are available at https://templates.scribing.io.

Surveillance, G2211, and Audio Handling

Longitudinal skin cancer care is where many Mohs surgeons do their most consequential cognitive work. When the surgeon says, "We'll see you every four months for full-body checks, sooner for anything new," the engine writes the interval to the plan, drafts the future visit reminder, and preserves the patient instructions. Over successive encounters, the record shows the surgeon as the continuing focal point for a serious, ongoing condition, which is the substance G2211 asks for. CMS permits G2211 alongside an E/M billed with Modifier 25, so the separation described above protects both.

Boilerplate weakens these claims. Phrases such as "complex patient with multiple comorbidities" invite denial. Merry AI keeps the specific history: the number of prior tumors, the transplant date, the dermatopathology trend, and the coordination with oncology.

Audio is held only in memory during the session. Once the transcript is generated and the clinician has approved the note, buffers are overwritten and discarded. No recording is saved to disk or browser storage, and none is used for model training. A Business Associate Agreement is executed before first use, and patient-facing summaries can carry an AI-assistance disclosure where state law, such as California AB 3030, requires it.

The clinician signs every note. The engine organizes the record, but judgment and attestation remain with the surgeon.