2026 ICD-10-CM Diagnosis Code J03.90Acute tonsillitis, unspecified
ICD-10-CM Codes›J00–J99›J00-J06›J03
- Billable — Valid for Submission
- Not Chronic
J03.90 is a billable ICD-10-CM diagnosis code for acute tonsillitis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 11 through 13, 152 through 153. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acute and chronic tonsillitis.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute adenoiditis
- Acute catarrhal tonsillitis
- Acute erythematous tonsillitis
- Acute follicular tonsillitis
- Acute gangrenous pharyngitis
- Acute gangrenous tonsillitis
- Acute glossitis
- Acute infection of tonsillar remnant
- Acute infective adenoiditis
- Acute lingual tonsillitis
- Acute tonsillitis
- Acute ulcerative pharyngitis
- Acute ulcerative tonsillitis
- Acute viral pharyngitis
- Acute viral tonsillitis
- Adenoiditis
- Bacterial tonsillitis
- Exudative pharyngitis
- Follicular tonsillitis
- Gangrenous pharyngitis
- Gangrenous tonsillitis
- Inflamed tonsils
- Lingular tonsillitis
- Pharyngotonsillitis
- Suppurative tonsillitis
- Tonsillitis
- Ulcer of pharynx
- Ulcer of tonsil
- Ulcerative pharyngitis
- Ulcerative tonsillitis
- Viral tonsillitis
Index to Diseases and InjuriesGuidance
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Tonsillitis
inflammation of the tonsils, especially the palatine tonsils but the adenoids (pharyngeal tonsils) and lingual tonsils may also be involved. tonsillitis usually is caused by bacterial infection. tonsillitis may be acute, chronic, or recurrent.Acute Tonsillitis
an acute inflammation of the tonsils caused by viruses or bacteria. signs and symptoms include fever, enlargement of the tonsils, difficulty swallowing, and enlargement of the regional lymph nodes.Tonsillitis
inflammation of the tonsillar tissue.
Patient EducationClinical
Tonsillitis
Tonsils are lumps of tissue at the back of the throat. There are two of them, one on each side. Along with the adenoids, tonsils are part of the lymphatic system. The lymphatic system clears away infection and keeps body fluids in balance. Tonsils and adenoids work by trapping the germs coming in through the mouth and nose.
The full article covers:
- What are tonsils?
- What is tonsillitis?
- What causes tonsillitis?
- Who is at risk for tonsillitis?
- Is tonsillitis contagious?
- What are the symptoms of tonsillitis?
- When does my child need to see a health care provider for tonsillitis?
- How is tonsillitis diagnosed?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert J03.90 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About J03.90Overview
What is the ICD-10 code for acute tonsillitis, unspecified?
The ICD-10-CM code for acute tonsillitis, unspecified is J03.90 (sometimes written as J0390). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is J03.90 (Acute tonsillitis, unspecified) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report acute tonsillitis, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does J03.90 group to?
When acute tonsillitis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 11, 12, 13, 152, 153, with relative weights from 0.7382 to 5.4541 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of J03.90?
Under the General Equivalence Mappings, acute tonsillitis, unspecified converts to ICD-9-CM 463 (acute tonsillitis). The mapping is approximate, so confirm the match fits the documentation.
