2026 ICD-10-CM Diagnosis Code L40.51Distal interphalangeal psoriatic arthropathy

ICD-10-CM Codes›L00–L99›L40-L45›L40

ICD-10-CM L40.51
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L40.51 is a billable ICD-10-CM diagnosis code for distal interphalangeal psoriatic arthropathy. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 545 through 547. Coders also document this condition as psoriatic arthritis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified chronic arthropathy and Other specified inflammatory condition of skin.

Code Identity

ICD-10-CM Code
L40.51
Billable Status
Yes — Valid for Submission
Code Describes
Distal interphalangeal psoriatic arthropathy
Short Description
Distal interphalangeal psoriatic arthropathy
Same as the full description in the CMS dataset.
Parent Code
L40.5
Arthropathic psoriasis

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL40-L45Papulosquamous disorders
CategoryL40Psoriasis
This CodeL40.51Distal interphalangeal psoriatic arthropathy

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Psoriatic arthritis
  • Psoriatic arthritis with distal interphalangeal joint involvement

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Arthropathy
      • distal interphalangeal, psoriatic
    • Arthropathy
      • psoriatic NEC
        • interphalangeal, distal
    • Psoriasis
      • arthropathic
        • distal interphalangeal

Clinical ClassificationClinical

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

CCSR MUS005
Other specified chronic arthropathy
Default principal diagnosis: inpatient No · outpatient No
CCSR SKN002
Other specified inflammatory condition of skin
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Psoriatic Arthritis

Psoriasis is a skin disease that causes itchy or sore patches of thick, red skin with silvery scales. You usually get them on your elbows, knees, scalp, back, face, palms and feet, but they can show up on other parts of your body.

Read the full article at MedlinePlus

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

Convert L40.51 to ICD-9-CMHistory

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

ICD-9-CM
696.0 Psoriatic arthropathy
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About L40.51Overview

Is L40.51 (Arthropathic psoriasis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report distal interphalangeal psoriatic arthropathy on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does L40.51 group to?

When distal interphalangeal psoriatic arthropathy is the principal diagnosis on an inpatient stay, it groups to MS-DRG 545, 546, 547, with relative weights from 0.8362 to 2.4817 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of L40.51?

Under the General Equivalence Mappings, distal interphalangeal psoriatic arthropathy converts to ICD-9-CM 696.0 (psoriatic arthropathy). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.