M35.2
BillableBehçet's disease
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M35.2 an HCC code?
Yes. M35.2 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 M35.2
For M35.2to 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 M35.2 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M35.2 is the ICD-10-CM diagnosis code for behçet's disease. Behçet's disease is a chronic inflammatory condition causing recurrent mouth ulcers, genital ulcers, eye inflammation, and skin lesions. M35.2 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, M35.2 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, M35.2 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.
Verify documentation specifies Behçet's disease diagnosis; this is a specific systemic vasculitis with characteristic manifestations. Because M35.2 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 M35.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify documentation specifies Behçet's disease diagnosis; this is a specific systemic vasculitis with characteristic manifestations
- •Document the specific organ systems involved (oral, genital, ocular, cutaneous) for complete clinical picture
Clinical Significance
Behçet's disease is a chronic multi-system vasculitis requiring long-term immunosuppressive therapy and specialized monitoring for serious complications like CNS involvement or major vessel disease. The unpredictable flare pattern and potential for organ-threatening manifestations necessitate ongoing subspecialty care.
Documentation Requirements
- ✓Documentation of characteristic clinical features (recurrent oral ulcers, genital ulcers, eye inflammation)
- ✓Evidence of pathergy test results if performed
- ✓Assessment of major organ involvement (CNS, cardiovascular, GI)
- ✓Description of disease activity and flare patterns
- ✓Current immunosuppressive therapy regimen
- ✓Ophthalmologic evaluation findings if eye involvement present
- ✓Exclusion of other causes of recurrent ulceration or vasculitis
Commonly Confused Codes
- •M31.9 — Necrotizing vasculopathy, unspecified (lacks Behçet's specific features)
- •K12.0 — Recurrent oral aphthae (symptom only, not systemic disease)
- •N76.6 — Ulceration of vulva in diseases classified elsewhere (symptom only)
- •H20.9 — Unspecified iridocyclitis (lacks systemic context)
- •M35.1 — Other overlap syndromes (different autoimmune pattern)