M00.851
BillableArthritis due to other bacteria, right hip
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M00.851 an HCC code?
Yes. M00.851 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 M00.851
For M00.851to 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 M00.851 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M00.851 is the ICD-10-CM diagnosis code for arthritis due to other bacteria, right hip. Bacterial infection causing inflammation and swelling in the right hip joint, caused by bacteria other than the most common types. M00.851 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, M00.851 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, M00.851 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.
Verify the specific bacterial organism is documented; if not specified, use M00.859 instead. Because M00.851 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 M00.851 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify the specific bacterial organism is documented; if not specified, use M00.859 instead
- •Ensure laterality (right hip) is clearly documented in the medical record before assigning this code
Clinical Significance
Bacterial arthritis of the right hip is a medical emergency that can rapidly destroy this critical weight-bearing joint. Early diagnosis and aggressive treatment are essential to prevent permanent disability, joint replacement necessity, and life-threatening complications.
Documentation Requirements
- ✓Confirmation of 'other bacteria' as causative organism
- ✓Specific documentation of right hip joint involvement
- ✓Microbiological evidence of bacterial infection
- ✓Clinical presentation consistent with septic arthritis
- ✓Evidence of immediate antibiotic therapy
- ✓Assessment of weight-bearing capacity and mobility
- ✓Laboratory markers of infection and inflammation
- ✓Exclusion of osteomyelitis versus isolated joint infection
Commonly Confused Codes
- •M00051 — Streptococcal arthritis of right hip (different organism)
- •M00015 — Staphylococcal arthritis of right hip (specific bacteria)
- •M06.851 — Other rheumatoid arthritis of right hip (autoimmune)
- •M16.11 — Unilateral primary osteoarthritis of right hip (degenerative)
- •M86.851 — Other osteomyelitis of right femur (bone infection)