M31.4Aortic arch syndrome [Takayasu]

M31.4 is the ICD-10-CM diagnosis code for aortic arch syndrome [Takayasu]. It belongs to category M31 (other necrotizing vasculopathies), block M30-M36 (systemic connective tissue disorders) 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 M31 (other necrotizing vasculopathies), M31.4 is specifically for aortic arch syndrome [Takayasu]. Related codes cover hypersensitivity angiitis (M31.0), thrombotic microangiopathy (M31.1), Lethal midline granuloma (M31.2), Wegener's granulomatosis (M31.3), giant cell arteritis with polymyalgia rheumatica (M31.5), other giant cell arteritis (M31.6), microscopic polyangiitis (M31.7), other specified necrotizing vasculopathies (M31.8) and 1 more.

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

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 has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 446.7 (Takayasu's disease).