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ICD-10-CM 2027 diagnosis code

M04.3VEXAS syndrome

✓ Billable / specificNew for 2027

M04.3 is a valid, billable ICD-10-CM code for vexas syndrome. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code last changed in FY2027 (effective October 1, 2026). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About M04.3

M04.3 is the ICD-10-CM diagnosis code for VEXAS syndrome. It belongs to category M04 (autoinflammatory syndromes), block M04 (autoinflammatory syndromes) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within M04 (autoinflammatory syndromes), M04.3 is specifically for VEXAS syndrome. Related codes cover periodic fever syndromes (M04.1), Cryopyrin-associated periodic syndromes (M04.2), other autoinflammatory syndromes (M04.8) and autoinflammatory syndrome, unspecified (M04.9).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 545 (Connective Tissue Disorders with MCC, relative weight 2.3892), DRG 546 (Connective Tissue Disorders with CC, relative weight 1.1745) and DRG 547 (Connective Tissue Disorders without CC/MCC, relative weight 0.7526), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It was added in FY2027, effective October 1, 2026.

Coding notes

Applicable toConditions and synonyms classified to this code
  • Vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory, somatic syndrome
Code alsoTwo codes may be needed; sequencing depends on circumstances
  • any associated conditions

Notes that apply from higher levels

Instructions written at a parent level also apply to M04.3.

› From M04 Autoinflammatory syndromes
Excludes2
  • Crohn's disease (K50.-)

Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to M04.3.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2027 (effective 10/1/2026): Added

Common questions about M04.3

Is M04.3 billable?

Yes. M04.3 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can M04.3 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict M04.3 as a principal diagnosis.

Is M04.3 a CC or MCC?

No. M04.3 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does M04.3 group to?

M04.3 is used in the MS-DRG v44.0 logic for MS-DRG 545 (Connective Tissue Disorders with MCC), MS-DRG 546 (Connective Tissue Disorders with CC) and MS-DRG 547 (Connective Tissue Disorders without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

Did M04.3 change for 2027?

Yes. For FY2027 (effective October 1, 2026) it was added to the code set.