M01.X62
BillableDirect infection of left knee 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.X62 an HCC code?
Yes. M01.X62 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.X62
For M01.X62to 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.X62 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M01.X62 is the ICD-10-CM diagnosis code for direct infection of left knee in infectious and parasitic diseases classified elsewhere. An infection in the left knee joint caused by a disease classified elsewhere, such as tuberculosis or a parasitic infection. M01.X62 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.X62 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.X62 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.
Document the specific underlying infectious disease to support accurate secondary code assignment. Because M01.X62 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.X62 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the specific underlying infectious disease to support accurate secondary code assignment
- •This code indicates the knee infection is a direct manifestation of another classified infectious condition
Clinical Significance
Direct infection of the left knee joint resulting from infectious or parasitic diseases classified elsewhere represents a critical condition requiring immediate and comprehensive treatment. The knee's role in mobility and weight-bearing makes this infection particularly concerning for functional outcomes and quality of life.
Documentation Requirements
- ✓Specific documentation of left knee joint infection
- ✓Primary code for underlying infectious or parasitic disease (A00-B99)
- ✓Clear evidence that knee infection is direct result of classified disease
- ✓Clinical assessment documenting knee joint inflammation and mobility impairment
- ✓Laboratory evidence supporting infectious process and systemic inflammation
- ✓Radiographic studies confirming knee joint involvement
- ✓Synovial fluid analysis from knee aspiration when performed
- ✓Comprehensive treatment plan for both systemic and local knee infection
Commonly Confused Codes
- •M00.962 — Pyogenic arthritis, left knee (routine bacterial knee infection)
- •M25.562 — Pain in left knee (joint symptoms without infectious cause)
- •M01.X61 — Direct infection of right knee in infectious diseases classified elsewhere
- •M23.92 — Unspecified internal derangement of left knee (mechanical problem)