ICD-10 Code M00.16 – Pneumococcal arthritis, knee (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M00.16 – Pneumococcal arthritis, knee
What it is
M00.16 identifies septic arthritis of the knee caused by pneumococcal infection. Use it when documentation confirms Streptococcus pneumoniae as the organism affecting the knee joint.
Clinical signs
Typical findings include acute knee pain, swelling, warmth, and limited range of motion. Fever may occur, but clinical features vary; refer to documentation for the confirmed organism and joint involved.
When to use this code
Use this code when the provider documents pneumococcal septic arthritis of the knee, or when culture or other clear documentation identifies S. pneumoniae as the cause. It is appropriate for the knee only, not another joint. Check documentation if the organism is not specified.
Do not use for
Do not use this code for noninfectious arthritis, unspecified septic arthritis, or pneumococcal infection without joint involvement. If the affected joint or organism is unclear, check documentation.
Coding tip
Code the organism and joint exactly as documented, and confirm that pneumococcal infection is linked to the knee.