ICD-10-CM 2027
ICD-10 code for allergic arteritis
From the official ICD-10-CM alphabetic index entry “Arteritis › allergic”. Page updated September 29, 2026.
About coding allergic arteritis
The ICD-10-CM code for allergic arteritis is M31.0 (Hypersensitivity angiitis).
Within M31 (other necrotizing vasculopathies), M31.0 is specifically for hypersensitivity angiitis. Related codes cover thrombotic microangiopathy (M31.1), Lethal midline granuloma (M31.2), Wegener's granulomatosis (M31.3), aortic arch syndrome [Takayasu] (M31.4), 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.
Common questions about allergic arteritis ICD-10 codes
What is the ICD-10 code for allergic arteritis?
- M31.0 — Hypersensitivity angiitis.
Is M31.0 billable?
- Yes. M31.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M31.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M31.0 as a principal diagnosis.
Is M31.0 a CC or MCC?
- M31.0 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.