2026 ICD-10-CM Diagnosis Code L40.59Other psoriatic arthropathy
ICD-10-CM Codes›L00–L99›L40-L45›L40
- Billable — Valid for Submission
- Risk Adjusts — HCC 93
- Chronic Condition
L40.59 is a billable ICD-10-CM diagnosis code for other 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.
For Medicare Advantage risk adjustment, L40.59 maps to CMS-HCC Category 93 (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders) under the V28 model, adding a risk factor of about 0.617 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
L40.59 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 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.
- Psoriatic arthritis
- Psoriatic dactylitis
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Arthropathy See Also: Arthritis; M12.9
psoriatic NEC L40.59
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Psoriatic arthritis
Psoriatic arthritis is a condition involving joint inflammation (arthritis) that usually occurs in combination with a skin disorder called psoriasis. Psoriasis is a chronic inflammatory condition characterized by patches of red, irritated skin that are often covered by flaky white scales.
Read the full article at MedlinePlus
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Convert L40.59 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About L40.59Overview
What is the ICD-10 code for other psoriatic arthropathy?
The ICD-10-CM code for other psoriatic arthropathy is L40.59 (sometimes written as L4059). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is L40.59 (Arthropathic psoriasis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other psoriatic arthropathy on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does L40.59 group to?
When other 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 L40.59?
Under the General Equivalence Mappings, other psoriatic arthropathy converts to ICD-9-CM 696.0 (psoriatic arthropathy). The mapping is approximate, so confirm the match fits the documentation.
What HCC is L40.59?
L40.59 (other psoriatic arthropathy) maps to CMS-HCC Category 93 (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders), commonly written as HCC 93, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 40 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 81.
Does L40.59 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, L40.59 adds a risk adjustment factor of about 0.617 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.288 to 0.617 depending on the payment segment). HCC 93 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 93 category page.
