M01.X61 ICD-10-CM Code: Direct infection of right knee in infectious and parasitic diseases classified elsewhere

Code

M01.X61

Description

Direct infection of right knee in infectious and parasitic diseases classified elsewhere

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 M01.X61 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for M01.X61

What This Code Means

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for M01.X61 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

• •This code represents a secondary knee joint infection manifestation of another primary infectious disease
• •Must be paired with a secondary diagnosis code identifying the underlying infectious or parasitic condition

Clinical Significance

Direct infection of the right knee joint secondary to classified infectious or parasitic diseases represents a serious condition affecting mobility and weight-bearing function. Knee infections can rapidly progress to joint destruction and require aggressive treatment to preserve function and prevent systemic complications.

Documentation Requirements

• ✓Clear documentation of right knee joint infection
• ✓Primary diagnosis of underlying infectious or parasitic disease
• ✓Evidence of direct causal relationship between systemic disease and knee infection
• ✓Physical examination documenting knee joint inflammation and functional limitation
• ✓Laboratory studies confirming infectious process and systemic involvement
• ✓Imaging studies showing knee joint involvement (X-ray, MRI, ultrasound)
• ✓Joint aspiration results with synovial fluid analysis when performed
• ✓Treatment plan addressing both underlying condition and knee-specific therapy

Commonly Confused Codes

• •M00.961: Pyogenic arthritis, right knee (bacterial infection not from classified disease)
• •M25.561: Pain in right knee (joint pain without infectious etiology)
• •M01.X62: Direct infection of left knee in infectious diseases classified elsewhere
• •M23.91: Unspecified internal derangement of right knee (mechanical knee problem)

Child Codes