2027 ICD-10-CM Diagnosis Code L40.1Generalized pustular psoriasis
ICD-10-CM Codes›L00–L99›L40-L45›L40
- Billable — Valid for Submission
- Chronic Condition
L40.1 is a billable ICD-10-CM diagnosis code for generalized pustular psoriasis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 606 through 607. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified inflammatory condition of skin.
L40.1 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 316 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
L40.1 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
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.
- Acute blistering eruption of skin
- Acute generalized pustular flare of preexisting plaque psoriasis
- Acute generalized pustular psoriasis de novo
- Acute pustular skin eruption
- Circinate and annular pustular psoriasis
- Exacerbation of psoriasis
- Exanthematous disorder
- Generalized pustular psoriasis
- Generalized pustular psoriasis of pregnancy
- Generalized pustular psoriasis, exanthematous type
- Infantile pustular psoriasis
- Localized pustular psoriasis
- Plaque psoriasis
- Plaque psoriasis with pustules
- Pustular psoriasis
- Vesicular eruption
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to L40.1: its own notes plus those printed at Chapter 12. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Impetigo herpetiformis
- Von Zumbusch's disease
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.
- 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.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name L40.1, its category, or a range that includes it.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Impetigo (any organism) (any site) (circinate) (contagiosa) (simplex) (vulgaris) L01.00
herpetiformis L40.1
nonobstetrical L40.1
Von Zumbusch's disease L40.1
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Generalized Pustular Psoriasis
a genetically heterogenous autoinflammatory condition characterized by sterile non-follicular pustules over wide areas of the body. it is a rare and severe form of psoriasis, and may result in death if not treated.Psoriasis
a common genetically determined, chronic, inflammatory skin disease characterized by rounded erythematous, dry, scaling patches. the lesions have a predilection for nails, scalp, genitalia, extensor surfaces, and the lumbosacral region. accelerated epidermopoiesis is considered to be the fundamental pathologic feature in psoriasis.
Patient EducationClinical
Psoriasis
Psoriasis is a skin disease that causes itchy or sore patches of thick, red skin with silvery scales. You usually get the patches on your elbows, knees, scalp, back, face, palms and feet, but they can show up on other parts of your body. Some people who have psoriasis also get a form of arthritis called psoriatic arthritis.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert L40.1 to ICD-9-CMHistory
Code HistoryHistory
Questions About L40.1Overview
What is the ICD-10 code for generalized pustular psoriasis?
The ICD-10-CM code for generalized pustular psoriasis is L40.1 (sometimes written as L401). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is L40.1 (Psoriasis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report generalized pustular psoriasis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does L40.1 group to?
When generalized pustular psoriasis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 607, 606, with relative weights from 0.8772 to 1.5721 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of L40.1?
Under the General Equivalence Mappings, generalized pustular psoriasis converts to ICD-9-CM 694.3 (impetigo herpetiformis) and 696.1 (other psoriasis). The mapping is approximate, so confirm the match fits the documentation.
Does L40.1 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: L40.1 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 316 (Psoriasis, Except with Arthropathy).
