M13.861 Other specified arthritis, right knee

Billable ICD-10-CM code, FY2026.

Applies from M13 Other arthritis

Excludes1 (never code together)

• arthrosis (M15-M19)
• osteoarthritis (M15-M19)

Applies from M13.8 Other specified arthritis

Applicable to

• Allergic arthritis

Excludes1 (never code together)

• osteoarthritis (M15-M19)

MS-DRG index

Defines the logic of DRG(s) 553-554 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 716.26 Allergic arthritis, lower leg (approximate)

Nearby codes

• M13.85 Other specified arthritis, hip
• M13.851 Other specified arthritis, right hip
• M13.852 Other specified arthritis, left hip
• M13.859 Other specified arthritis, unspecified hip
• M13.86 Other specified arthritis, knee
• M13.861 Other specified arthritis, right knee (this code)
• M13.862 Other specified arthritis, left knee
• M13.869 Other specified arthritis, unspecified knee
• M13.87 Other specified arthritis, ankle and foot
• M13.871 Other specified arthritis, right ankle and foot
• M13.872 Other specified arthritis, left ankle and foot