M01.X72
BillableDirect infection of left ankle and foot 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.X72 an HCC code?
Yes. M01.X72 maps to Bone/Joint/Muscle 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.X72
For M01.X72to 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.X72 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M01.X72 is the ICD-10-CM diagnosis code for direct infection of left ankle and foot in infectious and parasitic diseases classified elsewhere. Joint infection in the left ankle and foot caused by an infectious disease classified elsewhere, such as tuberculosis or a parasitic infection. M01.X72 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.X72 maps to Bone/Joint/Muscle Infections/Necrosis (HCC 92) with a community, non-dual, aged base RAF weight of 0.209. Under the older V24 model, M01.X72 mapped to the same category but with a base RAF weight of 0.482 — V28 recalibrated weights across the entire model. 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.
Requires a secondary code to identify the underlying infectious or parasitic disease causing the joint manifestation. Because M01.X72 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.X72 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Requires a secondary code to identify the underlying infectious or parasitic disease causing the joint manifestation
- •Confirm left-sided involvement is documented in the clinical record before assigning this laterality-specific code
Clinical Significance
Direct infection of the left ankle and foot joints caused by infectious or parasitic diseases classified elsewhere represents a serious condition with significant impact on mobility and independence. The complex anatomy of the foot and ankle requires specialized treatment approaches to preserve function and prevent disability.
Documentation Requirements
- ✓Specific documentation of left ankle and foot joint infection
- ✓Primary code for underlying infectious or parasitic disease (A00-B99)
- ✓Clear evidence that ankle/foot infection is direct result of classified disease
- ✓Clinical findings of ankle and foot joint inflammation and mobility limitations
- ✓Laboratory evidence of infection and systemic inflammatory response
- ✓Radiological confirmation of ankle and foot joint involvement
- ✓Synovial fluid analysis from accessible joints when aspiration performed
- ✓Comprehensive treatment plan for both systemic infection and foot/ankle preservation
Commonly Confused Codes
- •M00.972 — Pyogenic arthritis, left ankle and foot (routine bacterial infection)
- •M25.572 — Pain in left ankle and foot (joint symptoms without infectious cause)
- •M01.X71 — Direct infection of right ankle and foot in infectious diseases classified elsewhere
- •L03.117 — Cellulitis of left lower limb (soft tissue infection without joint involvement)