M01.X8
BillableDirect infection of vertebrae in infectious and parasitic diseases classified elsewhere
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M01.X8 an HCC code?
Yes. M01.X8 maps to Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis under the CMS-HCC V28 risk adjustment model (and Bone/Joint/Muscle Infections/Necrosis 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 M01.X8
For M01.X8to 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 M01.X8 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M01.X8 is the ICD-10-CM diagnosis code for direct infection of vertebrae in infectious and parasitic diseases classified elsewhere. Infection of the spine and vertebrae caused by an infectious disease classified elsewhere, such as tuberculosis or a parasitic infection. M01.X8 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering infectious arthropathies (m00-m02).
Under the CMS-HCC V28 risk adjustment model, M01.X8 maps to Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis (HCC 92) with a community, non-dual, aged base RAF weight of 0.479. Under the older CMS-HCC V24 model, M01.X8 maps to Bone/Joint/Muscle Infections/Necrosis (HCC 39) with a community, non-dual, aged base RAF weight of 0.401. 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 code indicates spinal involvement secondary to a documented infectious or parasitic disease. Because M01.X8 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 M01.X8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code indicates spinal involvement secondary to a documented infectious or parasitic disease
- •Always include the underlying infectious disease code to complete the clinical picture and justify the spinal involvement
Clinical Significance
Direct infection of the vertebrae secondary to classified infectious or parasitic diseases represents one of the most serious forms of infectious arthropathy, potentially leading to spinal cord compression, neurological deficits, and permanent disability. This condition requires immediate intervention and careful monitoring for neurological complications.
Documentation Requirements
- ✓Clear documentation of vertebral infection involving spine
- ✓Primary diagnosis of underlying infectious or parasitic disease
- ✓Evidence of direct relationship between systemic infection and spinal involvement
- ✓Neurological examination documenting any deficits or complications
- ✓Laboratory studies confirming infectious process and systemic involvement
- ✓Imaging studies showing vertebral involvement (MRI, CT, X-ray)
- ✓Tissue biopsy results when performed for microbiological confirmation
- ✓Treatment plan addressing both underlying disease and spinal stabilization needs
Commonly Confused Codes
- •M46.20 — Osteomyelitis of vertebra, unspecified region (bacterial bone infection)
- •M48.30 — Traumatic spondylopathy, site unspecified (trauma-related spinal condition)
- •A18.01 — Tuberculosis of spine (specific tuberculous spinal infection)
- •M50.30 — Other cervical disc degeneration (degenerative disc disease)