2027 ICD-10-CM Diagnosis Code L51.2Toxic epidermal necrolysis [Lyell]

ICD-10-CM Codes›L00–L99›L49-L54›L51

ICD-10-CM L51.2
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

L51.2 is a billable ICD-10-CM diagnosis code for toxic epidermal necrolysis [Lyell]. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 595 through 596. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 35 closely related codes. Coders also document this condition as lyell syndrome. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Allergic reactions and Other specified inflammatory condition of skin.

L51.2 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 162 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 162, ESRD (V21) category 162, and ESRD (V24) category 162 for payment year 2027.

Code Identity

ICD-10-CM Code
L51.2
Billable Status
Yes — Valid for Submission
Code Describes
Toxic epidermal necrolysis [Lyell]
Short Description
Toxic epidermal necrolysis [Lyell]
Same as the full description in the CMS dataset.
Parent Code
L51
Erythema multiforme

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL49-L54Urticaria and erythema
CategoryL51Erythema multiforme
This CodeL51.2Toxic epidermal necrolysis [Lyell]

Medicare Risk Adjustment (HCC)Billing

L51.2 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 162
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 162 · ESRD (V21): HCC 162 · ESRD (V24): HCC 162
ESRD V21 weights: 0.042 dialysis, 0.000–0.370 functioning graft · ESRD V24 weights: 0.155 dialysis, 0.000–1.053 functioning graft
Part D (RxHCC)
Not mapped
L51.2 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Lyell syndrome
  • Stevens-Johnson syndrome, toxic epidermal necrolysis spectrum
  • Toxic epidermal necrolysis caused by drug
  • Toxic epidermal necrolysis due to graft-versus-host disease
  • Toxic epidermal necrolysis due to infection

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to L51.2: its own notes plus those printed at L51, block L49-L54, and Chapter 12. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From L51 Erythema multiforme applies to 6 codes
  • staphylococcal scalded skin syndrome (L00)
  • Ritter's disease (L00)
From Block L49-L54 Urticaria and erythema applies to 33 codes

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 12 (L00-L99) Diseases of the skin and subcutaneous tissue applies to 1,001 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • lipomelanotic reticulosis (I89.8)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • viral warts (B07.-)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From L51 Erythema multiforme applies to 6 codes
  • 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-)
  • conjunctival edema (H11.42)
  • conjunctivitis (H10.22-)
  • corneal scars and opacities (H17.-)
  • corneal ulcer (H16.0-)
  • edema of eyelid (H02.84-)
  • inflammation of eyelid (H01.8-)
  • keratoconjunctivitis sicca (H16.22-)
  • mechanical lagophthalmos (H02.22-)
  • stomatitis (K12.-)
  • symblepharon (H11.23-)
  • code to identify percentage of skin exfoliation (L49.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name L51.2, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming L51.2: they are not reported together with it, unless the two conditions are unrelated.

  • L00 Staphylococcal scalded skin syndrome
    toxic epidermal necrolysis [Lyell] (L51.2)
  • Block L10-L14 Bullous disorders
    toxic epidermal necrolysis [Lyell] (L51.2)

Code First 2

These codes say to code first a condition named in the note, and L51.2 is one of the conditions named.

  • L49 Exfoliation due to erythematous conditions according to extent of body surface involved
    Toxic epidermal necrolysis (L51.2)
  • M14.8 Arthropathies in other specified diseases classified elsewhere
    erythema multiforme (L51.-) names L51.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ031
Allergic reactions
Default principal diagnosis: inpatient No · outpatient No
CCSR SKN002
Other specified inflammatory condition of skin
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Erythema Multiforme

    a skin and mucous membrane disease characterized by an eruption of macules, papules, nodules, vesicles, and/or bullae with characteristic bull's-eye lesions usually occurring on the dorsal aspect of the hands and forearms.

Patient EducationClinical

Skin Conditions

Your skin is your body's largest organ. It covers the entire outside of your body. There are many ways that your skin protects your body and helps keep you healthy. For example, it:

The full article covers:

  • What does your skin do?
  • What problems and conditions can affect your skin?
  • How can I keep my skin healthy?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert L51.2 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
695.15 Toxic epidrml necrolysis
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About L51.2Overview

What is the ICD-10 code for toxic epidermal necrolysis [Lyell]?

The ICD-10-CM code for toxic epidermal necrolysis [Lyell] is L51.2 (sometimes written as L512). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is L51.2 (Erythema multiforme) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report toxic epidermal necrolysis [Lyell] on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does L51.2 group to?

When toxic epidermal necrolysis [Lyell] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 596, 595, with relative weights from 1.1067 to 2.0230 depending on complications. Higher weights mean higher Medicare reimbursement.

Is L51.2 a CC or MCC?

CMS lists L51.2 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 35 closely related codes in its exclusion list.

Can L51.2 be reported with L00?

Not as a rule. The Excludes1 note at L51, which applies to L51.2, lists "staphylococcal scalded skin syndrome (L00)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does L51.2 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. L51.2 mapped to HCC 162 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 162 (Severe Skin Burn or Condition), ESRD (V21) category 162 (Severe Skin Burn or Condition), and ESRD (V24) category 162 (Severe Skin Burn or Condition).