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L40.1 ICD-10-CM Code: Generalized pustular psoriasis

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
2 inclusion terms
Risk adjustment
RxHCC V08 category 316

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

  • MS-DRG 606 — MINOR SKIN DISORDERS WITH MCC (MDC 09)
  • MS-DRG 607 — MINOR SKIN DISORDERS WITHOUT MCC (MDC 09)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for L40.1 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Impetigo herpetiformis
  • Von Zumbusch's disease

Don’t confuse L40.1 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of L40.1 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • L40.9— Specificity relationship (Review)

    Overlapping diagnoses in the same category.

    Overlapping codes in the same category — the documentation decides which is the more specific fit.

    What moves you there: A record that documents no more than “Psoriasis, unspecified” takes L40.9; specificity in the record moves it back here.

    Full comparison: L40.1 vs L40.9 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Code Overview

Generalized pustular psoriasis is a billable ICD-10-CM diagnosis code (L40.1).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (4)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name L40.1 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 2 Excludes1 notes: L01 — Impetigo, L12 — Pemphigoid.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 606 (MDC 09), DRG 607 (MDC 09).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):SKN002 — Other specified inflammatory condition of skin (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Other specified inflammatory condition of skin).

L29.1 — Pruritus scroti, L29.2 — Pruritus vulvae, L29.3 — Anogenital pruritus, unspecified, L29.8 — Other pruritus, L29.81 — Cholestatic pruritus, L29.89 — Other pruritus, L29.9 — Pruritus, unspecified, L30.4 — Erythema intertrigo, L30.5 — Pityriasis alba, L40.0 — Psoriasis vulgaris, L40.2 — Acrodermatitis continua, L40.3 — Pustulosis palmaris et plantaris, L40.4 — Guttate psoriasis, L40.50 — Arthropathic psoriasis, unspecified, L40.51 — Distal interphalangeal psoriatic arthropathy, L40.52 — Psoriatic arthritis mutilans, L40.53 — Psoriatic spondylitis, L40.54 — Psoriatic juvenile arthropathy, L40.59 — Other psoriatic arthropathy, L40.8 — Other psoriasis, +145 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Impetigo”, “Psoriasis”; these codes share that main term but sit in a different category of the Tabular List.

F54 — Psychological and behavioral factors associated with disorders or diseases classified elsewhere (psychogenic), K13.29 — Other disturbances of oral epithelium, including tongue (mouth), L01.00 — Impetigo, unspecified, L01.01 — Non-bullous impetigo (nonbullous), L01.02 — Bockhart's impetigo (Bockhart's), L01.03 — Bullous impetigo (neonatorum), L01.09 — Other impetigo (ulcerative), L30.5 — Pityriasis alba (furfuracea)

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

HIV Screening Test, Lipid Panel

Contextual Map

Every relationship of L40.1 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run L40.1 with these 2 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

  • L01 — Impetigo[Excludes1]: “impetigo herpetiformis (L40.1)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • L12 — Pemphigoid[Excludes1]: “impetigo herpetiformis (L40.1)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 09 — Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast[MDC crossing]: “Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 7,378 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Impetigo (any organism) (any site) (circinate) (contagiosa) (simplex) (vulgaris), herpetiformis[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Impetigo (any organism) (any site) (circinate) (contagiosa) (simplex) (vulgaris), herpetiformis, nonobstetrical[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Psoriasis, pustular (generalized)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Von Zumbusch's disease[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (14)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "L40.1 — Generalized pustular psoriasis." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/l40.1-generalized-pustular-psoriasis

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Generalized pustular psoriasis

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to L40.1 in its code family, with their registry titles.

View all codes in the L40 family