ICD-10 Code M00.279 – Other streptococcal arthritis, unspecified ankle and foot (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M00.279 – Other streptococcal arthritis, unspecified ankle and foot
What it is
This code identifies streptococcal infection causing arthritis in an ankle or foot joint, when the specific site is not further specified. Use it when documentation supports streptococcal septic arthritis and the ankle/foot location is described as unspecified.
Clinical signs
Typical findings include a painful, swollen, warm joint with reduced range of motion. Clinical features vary; refer to documentation for evidence of streptococcal joint infection and the affected ankle or foot joint.
When to use this code
Use M00.279 when the record states other streptococcal arthritis involving an ankle or foot joint, but does not identify the exact ankle or foot joint. It fits confirmed infectious arthritis due to streptococcal organisms, not nonspecific joint pain or inflammation. Check documentation if the organism or joint site is unclear.
Do not use for
Do not use this code for arthritis from non-streptococcal organisms, gout, rheumatoid arthritis, or traumatic joint conditions. If the infection site is more specific or documentation is incomplete, use the documented diagnosis instead.
Coding tip
Verify both the streptococcal cause and the ankle/foot location in the provider note before assigning M00.279.