L12 vs L51.2
L12 (Pemphigoid) compared with L51.2 (Toxic epidermal necrolysis [Lyell]), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. L12 carries an Excludes1 note covering L51.2: “toxic epidermal necrolysis [Lyell] (L51.2)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| L12Pemphigoid | L51.2Toxic epidermal necrolysis [Lyell] | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | L00-L99 — Diseases of the Skin and Subcutaneous Tissue (L00-L99) | L00-L99 — Diseases of the Skin and Subcutaneous Tissue (L00-L99) |
| Definition | Pemphigoid is a non-billable ICD-10-CM category code (L12). | Toxic epidermal necrolysis [Lyell] is a billable ICD-10-CM diagnosis code (L51.2). |
| Use additional code | — | code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) code to identify associated manifestations, such as: arthropathy associated with dermatological disorders (M14.8-) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources