New for FY2027 ICD-10-CM · October 1, 2026
M04.3: VEXAS syndrome
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is VEXAS syndrome. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
CMS-HCC V28
Not in the current CMS mapping file (FY2027-new)
CMS-HCC V24
Not in the current CMS mapping file (FY2027-new)
ESRD
Not in the current CMS mapping file (FY2027-new)
PACE
Not in the current CMS mapping file (FY2027-new)
RxHCC
Not in the current CMS mapping file (FY2027-new)
HHS-HCC
Not in the current CMS mapping file (FY2027-new)
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Source: M00-M99 (chapter, inherited).
Excludes2
arthropathic psoriasis (L40.5-)
Source: M00-M99 (chapter, inherited).
Excludes2
certain conditions originating in the perinatal period (P04-P96)
Source: M00-M99 (chapter, inherited).
Excludes2
certain infectious and parasitic diseases (A00-B99)
Source: M00-M99 (chapter, inherited).
Excludes2
compartment syndrome (traumatic) (T79.A-)
Source: M00-M99 (chapter, inherited).
Excludes2
complications of pregnancy, childbirth and the puerperium (O00-O9A)
Source: M00-M99 (chapter, inherited).
Excludes2
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
Source: M00-M99 (chapter, inherited).
Excludes2
endocrine, nutritional and metabolic diseases (E00-E88)
Source: M00-M99 (chapter, inherited).
Excludes2
injury, poisoning and certain other consequences of external causes (S00-T88)
Source: M00-M99 (chapter, inherited).
Excludes2
neoplasms (C00-D49)
Source: M00-M99 (chapter, inherited).
Excludes2
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: M00-M99 (chapter, inherited).
Excludes2
Crohn's disease (K50.-)
Source: M04 (category, inherited).
Instructional note
Vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory, somatic syndrome
Source: M04.3 (self, direct).
Code also
any associated conditions
Source: M04.3 (self, direct).
Compare the FY2027 additions, removals and billable-status changes
What does M04.3 mean in FY2027?
The official ICD-10-CM descriptor is VEXAS syndrome. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
When did M04.3 become an ICD-10-CM code?
M04.3 is new for FY2027 ICD-10-CM, effective October 1, 2026. It is absent from the FY2026 April order file. Use the code set that applies to the encounter or inpatient discharge date, and check the official Tabular instructions.
Is M04.3 billable in FY2027?
The FY2027 order file marks M04.3 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does M04.3 map to an HCC?
M04.3 is not in the current CMS mapping file (it is new for FY2027), and CMS has not yet published payment year 2028 mappings. No HCC category or RAF coefficient is shown.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.