Is ICD-10-CM code L40 billable?

No, L40 (Psoriasis) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code L40 belong to?

L40 belongs to Chapter 12 of the ICD-10-CM tabular list: L00–L99 (Diseases of the Skin and Subcutaneous Tissue).

L40Not billable, use a more specific code below

Psoriasis

In Papulosquamous disorders (L40-L45), chapter 12: Diseases of the Skin and Subcutaneous Tissue

13 billable codes under L40: none are a CC or MCC; 6 map to HCC 93 (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders).An HCC counts toward a Medicare Advantage patient's risk score.

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers assigning pressure ulcer codes by site and stage, including unstageable, healing, healed, and progressing ulcers, and coding healing or progressing non-pressure chronic ulcers.

Pressure ulcer stage codes (page 58)
Non-Pressure Chronic Ulcers (page 60)

Read Section I.C.12 (page 58)

All codes under L40

L40 can't be used on a claim. Pick a billable code below; grey headings group them.

L40 MS-DRGs

As the principal diagnosis, the billable codes under L40 group to these 7 MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 545 Connective Tissue Disorders with MCC (6 of 13 codes)
DRG 546 Connective Tissue Disorders with CC (6 of 13 codes)
DRG 547 Connective Tissue Disorders without CC/MCC (6 of 13 codes)
DRG 595 Major Skin Disorders with MCC (6 of 13 codes)
DRG 596 Major Skin Disorders without MCC (6 of 13 codes)
DRG 606 Minor Skin Disorders with MCC (1 of 13 codes)
DRG 607 Minor Skin Disorders without MCC (1 of 13 codes)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

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.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.