M02.869
BillableOther reactive arthropathies, unspecified knee
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M02.869 an HCC code?
Yes. M02.869 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 M02.869
For M02.869to 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 M02.869 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M02.869 is the ICD-10-CM diagnosis code for other reactive arthropathies, unspecified knee. Joint inflammation in the knee that develops as a reaction to an infection or other trigger elsewhere in the body, with the specific knee not identified as right or left. M02.869 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, M02.869 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, M02.869 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 when the reactive arthropathy affects the knee but laterality (right vs. left) is not documented. Because M02.869 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 M02.869 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code when the reactive arthropathy affects the knee but laterality (right vs. left) is not documented
- •Reactive arthropathies typically follow infections like gastroenteritis or urinary tract infections; review clinical documentation for the triggering condition
Clinical Significance
This diagnosis represents reactive arthropathy affecting the knee when laterality is not specified in documentation. The unspecified nature may indicate bilateral knee involvement, incomplete clinical assessment, or inadequate documentation, potentially impacting treatment specificity and monitoring.
Documentation Requirements
- ✓Clinical evidence of knee joint inflammation (swelling, pain, stiffness, effusion)
- ✓Documentation of reactive nature - inflammation secondary to remote infection
- ✓Confirmation that knee laterality is truly unspecified or bilateral involvement
- ✓Evidence ruling out direct septic arthritis or other infectious arthropathies
- ✓Documentation of triggering infection or infectious process (if identified)
- ✓Physical examination findings consistent with knee arthritis
- ✓Exclusion of other arthropathy types (rheumatoid, osteoarthritis, crystal arthropathy)
- ✓Assessment of functional impact on mobility and weight-bearing
Commonly Confused Codes
- •M02.861 — Other reactive arthropathies, right knee (when laterality is documented)
- •M02.862 — Other reactive arthropathies, left knee (when laterality is documented)
- •M00.069 — Staphylococcal arthritis, unspecified knee (infectious vs reactive)
- •M06.069 — Rheumatoid arthritis, unspecified knee (autoimmune vs reactive)
- •M25.569 — Pain in unspecified knee (symptom vs specific arthropathy diagnosis)