ICD-10 Code M00.9 – Pyogenic arthritis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M00.9 – Pyogenic arthritis, unspecified
What it is
M00.9 identifies pyogenic arthritis when the infecting organism or joint site is not specified. Use it for a bacterial joint infection that is documented as pyogenic but not further detailed.
Clinical signs
Typical findings include acute joint pain, swelling, warmth, and reduced range of motion. Fever may occur, but clinical features vary; refer to documentation.
When to use this code
Use M00.9 when the record clearly states pyogenic arthritis and does not name the organism or affected joint. It also fits when the provider documents septic arthritis without additional detail. If the note later identifies a specific site or organism, code to the more specific option.
Do not use for
Do not use this code for noninfectious inflammatory arthritis or chronic degenerative joint disease. If the documentation identifies a specific organism, joint, or other cause, check documentation for a more precise code.
Coding tip
Review the assessment and culture results together so you do not miss a more specific pyogenic arthritis code.