Is ICD-10-CM code M04.3 billable?

Yes, M04.3 (VEXAS syndrome) is a billable ICD-10-CM diagnosis code, valid for reimbursement on HIPAA-covered transactions for FY2027.

What chapter does ICD-10-CM code M04.3 belong to?

M04.3 belongs to Chapter 13 of the ICD-10-CM tabular list: M00–M99 (Diseases of the Musculoskeletal System and Connective Tissue).

Is M04.3 a new ICD-10-CM code for 2027?

Yes, M04.3 was added or revised in the FY2027 ICD-10-CM update, effective October 1, 2026, as published by the Centers for Medicare and Medicaid Services (CMS).

M04.3Billable, valid for claims from October 1, 2026New for FY2027

VEXAS syndrome

Under M04 Autoinflammatory syndromes, chapter 13: Diseases of the Musculoskeletal System and Connective Tissue

M04.3 is billable and valid on claims for FY 2027. If the record has more detail, check the other codes under M04 below.
As a secondary diagnosis it is not a CC or MCC, so it doesn't raise the MS-DRG payment.

Also indexed as: Syndrome, vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory, somatic; Syndrome, VEXAS

Instructional notes

Includes: conditions that are coded here

Vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory, somatic syndrome

Code also: add a code for this too, order depends on the encounter

any associated conditions

Also applies, from M04: Autoinflammatory syndromes

These notes sit on M04 and apply to every code under it, including M04.3.

Excludes2: not included here, code separately if applicable

Crohn's disease (K50.-)

Other codes under M04

Autoinflammatory syndromes

M04.1Periodic fever syndromes
M04.2Cryopyrin-associated periodic syndromes
M04.3VEXAS syndrome(this code)
M04.8Other autoinflammatory syndromes
M04.9Autoinflammatory syndrome, unspecified

MS-DRGs

As the principal diagnosis, this code groups to these MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

About the condition

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

Autoimmune Diseases

Your immune system protects you from disease and infection by attacking germs that get into your body, such as viruses and bacteria. Your immune system can tell that the germs aren't part of you, so it destroys them. If you have an autoimmune disease, your immune system attacks the healthy cells of your organs and tissues by mistake.

Code history

Added in FY2027 (effective October 1, 2026). Before that, these cases were coded as M04.8 (Other autoinflammatory syndromes). No changes since.