What is ICD-10 code M30.1?

M30.1 is the ICD-10-CM diagnosis code for Polyarteritis with lung involvement [Churg-Strauss]. A rare inflammatory disease (Churg-Strauss syndrome) that affects blood vessels and causes inflammation in the lungs along with other systemic symptoms. M30.1 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. M30.1 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. M30.1 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. M30.1 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for M30.1?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For M30.1, V28 maps to Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis at RAF 0.818 while V24 mapped to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease at RAF 0.421. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting M30.1?

This condition is also known as eosinophilic granulomatosis with polyangiitis (EGPA); document the preferred terminology used Specify the extent of lung involvement and any other affected organs for complete clinical picture Because M30.1 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

2026 ICD-10-CM M30.1: Polyarteritis with lung

ICD-10-CM Code View

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Code lookupM30.1Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Systemic connective tissue disorders (M30-M36)

M30.1

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Polyarteritis with lung involvement [Churg-Strauss]

A rare inflammatory disease (Churg-Strauss syndrome) that affects blood vessels and causes inflammation in the lungs along with other systemic symptoms.

Buddy Insight

Churg-Strauss syndrome (Eosinophilic Granulomatosis with Polyangiitis) is a rare, life-threatening systemic vasculitis with prominent lung involvement and eosinophilia.

CMS-HCC V28

Mapped

HCC 278

Idiopathic Pulmonary Fibrosis...

RAF 0.818

CMS-HCC V24

Mapped

HCC 40

Rheumatoid Arthritis and Infl...

RAF 0.421

ACA/HHS

Mapped

HCC 56

HHS-HCC 56

Varies by metal level

ESRD/PACE

Mapped

HCC 40

Rheumatoid Arthritis and Infl...

RAF 0.058

RXHCC

Mapped

HCC 84

Vasculitis and Other Autoimmu...

RAF 0.113

Code Book Path

Official

M30Polyarteritis nodosa and related conditions

M30.1Polyarteritis with lung involvement [Churg-Strauss]

Inclusion Terms

Official

Allergic granulomatous angiitis
Eosinophilic granulomatosis with polyangiitis [EGPA]

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for M30.1 in this effective period.

Related Child Codes

Official

M30.0Polyarteritis nodosa

M30.2Juvenile polyarteritis

M30.3Mucocutaneous lymph node syndrome [Kawasaki]

M30.8Other conditions related to polyarteritis nodosa

Includes

Official

ICD-10-CM does not list Includes notes for M30.1 in this effective period.

Excludes 1

Official

microscopic polyarteritis (M31.7)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for M30.1 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for M30.1 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for M30.1 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Clinical triad of asthma, eosinophilia, and systemic vasculitis

Pulmonary involvement documentation

Biopsy showing eosinophilic infiltration and necrotizing vasculitis

Laboratory evidence of eosinophilia

MEAT Support

HCC Buddy guidance

Clinical triad of asthma, eosinophilia, and systemic vasculitis

Pulmonary involvement documentation

Biopsy showing eosinophilic infiltration and necrotizing vasculitis

Laboratory evidence of eosinophilia

Audit Caution

HCC Buddy guidance

Coding only asthma component without recognizing systemic vasculitis

Missing the lung involvement that distinguishes from classic PAN

Confusing with other ANCA-associated vasculitides

Using only eosinophilia codes without systemic component

Common Mistakes

HCC Buddy guidance

M30.0 — Polyarteritis nodosa (without lung involvement)

J45.9 — Asthma, unspecified (when only respiratory symptoms are coded)

M31.30 — Wegener's granulomatosis without renal involvement

D72.1 — Eosinophilia (when only blood abnormality is coded)

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is M30.1 an HCC code?

Yes. M30.1 (Polyarteritis with lung involvement [Churg-Strauss]) maps to Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis under the CMS-HCC V28 risk adjustment model (and Rheumatoid Arthritis and Inflammatory Connective Tissue Disease under V24), with a community non-dual aged RAF of 0.818. It is billable for payment year 2026.

Coder answer: M30.1 is billable and maps to V28 HCC 278, Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: M30.1
Description: Polyarteritis with lung involvement [Churg-Strauss]
HCC (V28): HCC 278 — Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis
RAF: 0.818
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 278, Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis

0.818

V24HCC 40, Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.421

ESRDHCC 40, Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.058

RxHCCHCC 84, Vasculitis and Other Autoimmune Disorders

0.113

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work M30.1 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for M30.1

For M30.1 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed M30.1 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

M30.1 is the ICD-10-CM diagnosis code for polyarteritis with lung involvement [churg-strauss]. A rare inflammatory disease (Churg-Strauss syndrome) that affects blood vessels and causes inflammation in the lungs along with other systemic symptoms. M30.1 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering systemic connective tissue disorders (m30-m36).

Under the CMS-HCC V28 risk adjustment model, M30.1 maps to Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis (HCC 278) with a community, non-dual, aged base RAF weight of 0.818. Under the older CMS-HCC V24 model, M30.1 maps to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease (HCC 40) with a community, non-dual, aged base RAF weight of 0.421. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

This condition is also known as eosinophilic granulomatosis with polyangiitis (EGPA); document the preferred terminology used. Because M30.1 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for M30.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This condition is also known as eosinophilic granulomatosis with polyangiitis (EGPA); document the preferred terminology used
•Specify the extent of lung involvement and any other affected organs for complete clinical picture

Clinical Significance

Churg-Strauss syndrome (Eosinophilic Granulomatosis with Polyangiitis) is a rare, life-threatening systemic vasculitis with prominent lung involvement and eosinophilia. The condition requires immediate aggressive treatment and has a high risk of organ damage and mortality if untreated.