HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Systemic connective tissue disorders (M30-M36)
M30.0
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidancePolyarteritis nodosa
A serious inflammatory disease that affects medium-sized arteries throughout the body, causing tissue damage and organ dysfunction.
Buddy Insight
Polyarteritis nodosa is a serious systemic necrotizing vasculitis affecting medium-sized arteries, requiring aggressive immunosuppressive therapy and close monitoring for organ involvement.
CMS-HCC V28
MappedHCC 94
RAF 0.0
CMS-HCC V24
MappedHCC 40
RAF 0.307
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 40
RAF 0.0
RXHCC
MappedHCC 84
RAF 0.0
Code Trumping
Basket needed
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for M30.0 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for M30.0 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for M30.0 in this effective period.
Excludes 1
Official- microscopic polyarteritis (M31.7)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for M30.0 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for M30.0 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for M30.0 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is M30.0 an HCC code?
Yes. M30.0 maps to Reactive and Specified Arthropathies under the CMS-HCC V28 risk adjustment model (and Rheumatoid Arthritis and Inflammatory Connective Tissue Disease under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.
MEAT Criteria for M30.0
For M30.0to 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 M30.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M30.0 is the ICD-10-CM diagnosis code for polyarteritis nodosa. A serious inflammatory disease that affects medium-sized arteries throughout the body, causing tissue damage and organ dysfunction. M30.0 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, M30.0 maps to Reactive and Specified Arthropathies (HCC 94) with a community, non-dual, aged base RAF weight of 0.000. Under the older CMS-HCC V24 model, M30.0 maps to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease (HCC 40) with a community, non-dual, aged base RAF weight of 0.307. 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.
Document which organs or systems are involved as this affects severity and treatment planning. Because M30.0 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 M30.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document which organs or systems are involved as this affects severity and treatment planning
- •Distinguish from other vasculitides; polyarteritis nodosa specifically affects medium-sized arteries
Clinical Significance
Polyarteritis nodosa is a serious systemic necrotizing vasculitis affecting medium-sized arteries, requiring aggressive immunosuppressive therapy and close monitoring for organ involvement. The condition carries significant morbidity and mortality risk, necessitating specialized rheumatologic care and multisystem monitoring.
Documentation Requirements
- ✓Clinical evidence of systemic necrotizing arteritis
- ✓Biopsy confirmation or characteristic angiographic findings
- ✓Documentation of affected organ systems
- ✓Laboratory evidence supporting vasculitis diagnosis
- ✓Exclusion of other forms of vasculitis
- ✓Assessment of disease activity and severity
- ✓Documentation of treatment response
- ✓Monitoring for complications and organ damage