M02.879 ICD-10-CM Code: Other reactive arthropathies, unspecified ankle and foot

Code

M02.879

Description

Other reactive arthropathies, unspecified ankle and foot

HCC (V28)

HCC 92 — Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis

RAF reference coefficient

0.479

Billable

Yes

Payment year

2026

HCC Category Mapping

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work M02.879 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for M02.879

What This Code Means

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for M02.879 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 bilateral involvement is present or when laterality cannot be determined from documentation
• •Query the provider if laterality can be determined, as more specific codes (M02.871 or M02.872) are preferred

Clinical Significance

This diagnosis represents reactive arthropathy affecting the ankle and foot when laterality is not specified in documentation. The unspecified nature may indicate bilateral involvement, incomplete clinical assessment, or inadequate documentation, potentially affecting treatment precision and functional assessment.

Documentation Requirements

• ✓Clinical evidence of ankle and/or foot joint inflammation (swelling, pain, stiffness)
• ✓Documentation of reactive nature - inflammation secondary to remote infection
• ✓Confirmation that ankle/foot 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 ankle/foot arthritis
• ✓Exclusion of other arthropathy types (rheumatoid, osteoarthritis, crystal arthropathy)
• ✓Assessment of functional impact on ambulation and balance

Commonly Confused Codes

• •M02.871: Other reactive arthropathies, right ankle and foot (when laterality documented)
• •M02.872: Other reactive arthropathies, left ankle and foot (when laterality documented)
• •M00.079: Staphylococcal arthritis, unspecified ankle and foot (infectious vs reactive)
• •M06.079: Rheumatoid arthritis, unspecified ankle and foot (autoimmune vs reactive)
• •M25.579: Pain in unspecified ankle and foot (symptom vs specific arthropathy diagnosis)

Child Codes