M00.829
BillableArthritis due to other bacteria, unspecified elbow
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M00.829 an HCC code?
Yes. M00.829 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 M00.829
For M00.829to 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 M00.829 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M00.829 is the ICD-10-CM diagnosis code for arthritis due to other bacteria, unspecified elbow. Infection and inflammation of the elbow joint caused by bacteria other than the common ones typically associated with arthritis, when the specific elbow is not identified. M00.829 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, M00.829 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, M00.829 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.
Use this code only when laterality cannot be determined from documentation. Because M00.829 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 M00.829 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when laterality cannot be determined from documentation
- •Query the provider if documentation suggests a specific elbow but laterality is unclear
Clinical Significance
Bacterial arthritis of unspecified elbow indicates a serious joint infection requiring immediate treatment, though the documentation lacks laterality specificity. This condition can rapidly progress to joint destruction and requires urgent antibiotic therapy and close monitoring.
Documentation Requirements
- ✓Evidence of 'other bacteria' causing infection (not routine pathogens)
- ✓Documentation of elbow joint involvement without laterality
- ✓Laboratory confirmation of bacterial etiology
- ✓Signs and symptoms of infectious arthritis
- ✓Treatment with systemic antibiotics documented
- ✓Assessment of joint mobility and function
- ✓Inflammatory laboratory values (elevated WBC, ESR, CRP)
- ✓Query for laterality specification in subsequent encounters
Commonly Confused Codes
- •M00.821/M00.822 — Same condition with specific laterality documented
- •M00029 — Streptococcal arthritis of unspecified elbow (different organism)
- •M00019 — Staphylococcal arthritis of unspecified elbow (different bacteria)
- •M06.829 — Other rheumatoid arthritis of unspecified elbow (autoimmune)
- •M19.029 — Primary osteoarthritis of unspecified elbow (degenerative)