ICD-10 Code J03.9 – Acute tonsillitis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J03.9 – Acute tonsillitis, unspecified
What it is
J03.9 identifies an acute tonsil infection when the provider does not document a specific organism or type. Use it for short-term tonsillar inflammation or infection that is otherwise unspecified.
Clinical signs
Typical findings include sore throat, enlarged or erythematous tonsils, and painful swallowing. Fever, exudate, or tender cervical nodes may be present, but clinical features vary; refer to documentation.
When to use this code
Use J03.9 when the record states acute tonsillitis and gives no further detail about the cause or subtype. It also fits when the provider documents tonsillitis without identifying streptococcal, viral, or recurrent disease.
If the note later specifies a different acute tonsillitis type, code the documented condition instead. Check documentation when the encounter includes pharyngitis, peritonsillar abscess, or chronic tonsillar disease.
Do not use for
Do not use J03.9 for chronic or recurrent tonsillitis, or for tonsillitis with a documented specific cause when another code is assigned. Do not use it for isolated sore throat without tonsillar involvement.
Coding tip
Code the most specific tonsillitis diagnosis documented, and query if the chart only says “tonsil infection” or “throat infection.”