M01.X52
BillableDirect infection of left hip 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.X52 an HCC code?
Yes. M01.X52 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.X52
For M01.X52to 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.X52 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M01.X52 is the ICD-10-CM diagnosis code for direct infection of left hip in infectious and parasitic diseases classified elsewhere. An infection in the left hip joint caused by a disease classified elsewhere, such as tuberculosis or a parasitic infection. M01.X52 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.X52 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.X52 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.
Document the underlying infectious disease clearly to ensure proper secondary code assignment. Because M01.X52 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.X52 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the underlying infectious disease clearly to ensure proper secondary code assignment
- •Hip infections from systemic diseases require both the manifestation code and the underlying disease code
Clinical Significance
Direct infection of the left hip joint caused by infectious or parasitic diseases classified elsewhere represents a critical condition requiring immediate intervention. Hip joint infections can rapidly progress to sepsis, osteomyelitis, and irreversible joint destruction, making this a high-priority diagnosis for comprehensive care.
Documentation Requirements
- ✓Specific documentation of left hip joint infection
- ✓Primary code for underlying infectious or parasitic disease (A00-B99)
- ✓Clear evidence that hip infection is direct result of classified disease
- ✓Clinical findings of hip joint inflammation, pain, and mobility limitations
- ✓Laboratory evidence of infection and systemic inflammatory response
- ✓Radiological confirmation of hip joint involvement and complications
- ✓Synovial fluid analysis from hip aspiration when performed
- ✓Comprehensive treatment plan for both systemic infection and hip preservation
Commonly Confused Codes
- •M00.952 — Pyogenic arthritis, left hip (routine bacterial hip infection)
- •M25.552 — Pain in left hip (joint symptoms without infectious cause)
- •M01.X51 — Direct infection of right hip in infectious diseases classified elsewhere
- •M87.052 — Idiopathic aseptic necrosis of left femoral head (non-infectious necrosis)