M31.7 Microscopic polyangiitis

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

Applicable to

• Microscopic polyarteritis

Excludes1 (never code together)

• polyarteritis nodosa (M30.0)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 94 — Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue 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)

• 446.0 Polyarteritis nodosa (approximate)

Code annotations containing back-references to M31.7

Back-references to M31.7

• Type 2 Excludes: I77.82 Antineutrophilic cytoplasmic antibody [ANCA] vasculitis ("microscopic polyangiitis (M31.7)")
• Type 1 Excludes: M30 Polyarteritis nodosa and related conditions ("microscopic polyarteritis (M31.7)")
• Code First: N08 Glomerular disorders in diseases classified elsewhere ("microscopic polyangiitis (M31.7)")

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 M31.7

• Disorder (of) › glomerular (in) › microscopic polyangiitis
• Glomerulonephritis › in (due to) › microscopic polyangiitis
• Microscopic polyangiitis (polyarteritis)
• Polyangiitis › microscopic
• Polyarteritis › microscopic
• Polyneuropathy (peripheral) › in (due to) › microscopic polyangiitis

Nearby codes

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