M31.4 Aortic arch syndrome [Takayasu]

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Risk adjustment (HCC)

• CMS-HCC V28: HCC 93 — Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders
• CMS-HCC V22: HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
• RxHCC V08: HCC 84 — Systemic Lupus Erythematosus and Other Systemic Connective Tissue Disorders
• ESRD V24: HCC 40

MS-DRG index

Defines the logic of DRG(s) 545-547 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 446.7 Takayasu's disease

Code annotations containing back-references to M31.4

Back-references to M31.4

• Type 1 Excludes: I77.6 Arteritis, unspecified ("aortic arch (M31.4)")

Back-references to M31

• Type 2 Excludes: I77 Other disorders of arteries and arterioles ("collagen (vascular) diseases (M30-M36)")
• Type 2 Excludes: J82 Pulmonary eosinophilia, not elsewhere classified ("pulmonary eosinophilia due to systemic connective tissue disorders (M30-M36)")
• Code First: J84.170 Interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere ("systemic connective tissue disorders (M30-M36)")
• Type 1 Excludes: L94 Other localized connective tissue disorders ("systemic connective tissue disorders (M30-M36)")

Diagnosis Index entries for M31.4

• Arteritis › aortic arch
• Arteritis › brachiocephalic
• Arteritis › young female aortic arch syndrome
• Disease, diseased › pulseless
• Syndrome › aortic › arch
• Takayasu's disease or syndrome

Nearby codes

• M31.19 Other thrombotic microangiopathy
• M31.2 Lethal midline granuloma
• M31.3 Wegener's granulomatosis
• M31.30 Wegener's granulomatosis without renal involvement
• M31.31 Wegener's granulomatosis with renal involvement
• M31.4 Aortic arch syndrome [Takayasu] (this code)
• M31.5 Giant cell arteritis with polymyalgia rheumatica
• M31.6 Other giant cell arteritis
• M31.7 Microscopic polyangiitis
• M31.8 Other specified necrotizing vasculopathies
• M31.9 Necrotizing vasculopathy, unspecified