M00.811
BillableArthritis due to other bacteria, right shoulder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M00.811 an HCC code?
Yes. M00.811 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 M00.811
For M00.811to 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 M00.811 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M00.811 is the ICD-10-CM diagnosis code for arthritis due to other bacteria, right shoulder. A bacterial infection of the right shoulder joint caused by bacteria other than streptococcus, resulting in inflammation and pain. M00.811 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, M00.811 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, M00.811 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 specific bacterial organism causing the infection for treatment planning. Because M00.811 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 M00.811 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the specific bacterial organism causing the infection for treatment planning
- •Confirm right shoulder involvement is clearly documented in the clinical record
Clinical Significance
Septic arthritis of the right shoulder caused by other specified bacterial organisms is a serious infectious condition requiring emergent treatment with intravenous antibiotics and often surgical intervention. Involvement of the right shoulder, a large weight-bearing or major joint, increases the risk of significant functional impairment and may require arthroscopic or open surgical drainage. This condition reflects high healthcare complexity and resource needs, making it significant for risk adjustment.
Documentation Requirements
- ✓Provider documentation explicitly stating other bacterial septic arthritis or pyogenic arthritis with identified causative organism
- ✓Synovial fluid analysis results (cell count, Gram stain, crystal analysis to rule out gout/pseudogout)
- ✓Culture and sensitivity results identifying the specific other bacterial organism, or clinical rationale if culture-negative
- ✓Clinical signs and symptoms of joint infection (acute onset joint pain, swelling, warmth, erythema, fever, limited range of motion)
- ✓Documentation confirming right-sided involvement with imaging or examination findings specific to that side
- ✓Treatment plan including antibiotic regimen, duration, and any surgical intervention (arthrocentesis, irrigation and debridement, arthroscopy)
Commonly Confused Codes
- •M00.0x (Staphylococcal arthritis) — When culture confirms Staphylococcus species, assign M00.0x instead; M00.8x is for other specified bacteria not classified in M00.0-M00.2
- •M00.1x (Pneumococcal arthritis) — If the organism is identified as Streptococcus pneumoniae, use M00.1x instead of M00.8x
- •M00.2x (Other streptococcal arthritis) — For streptococcal species other than pneumococcus, use M00.2x; M00.8x covers organisms like Haemophilus influenzae, Escherichia coli, Pseudomonas, and Neisseria gonorrhoeae (if not M00.9)