ICD-10 Code J03.90 – Acute tonsillitis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J03.90 – Acute tonsillitis, unspecified
What it is
J03.90 identifies an acute inflammation of the tonsils when the record does not specify the cause or type. Use it when the documentation says acute tonsillitis but gives no further detail.
Clinical signs
Typical findings include sore throat, enlarged or red tonsils, painful swallowing, and fever. Clinical features vary; refer to documentation.
When to use this code
Use this code when the clinician documents acute tonsillitis without naming streptococcal, viral, or other specified etiology. It also fits when the note confirms tonsillar infection but lacks detail needed for a more specific code.
Do not use for
Do not use J03.90 if the record specifies a different acute tonsillitis type or a related condition such as chronic tonsillitis. Check documentation for a more precise diagnosis before assigning an unspecified code.
Coding tip
Choose the most specific tonsillitis code supported by the note; if the cause is not documented, J03.90 is appropriate.