2026 ICD-10-CM Diagnosis Code J03.00Acute streptococcal tonsillitis, unspecified

ICD-10-CM Codes›J00–J99›J00-J06›J03

ICD-10-CM J03.00
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J03.00 is a billable ICD-10-CM diagnosis code for acute streptococcal 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. Coders also document this condition as acute bacterial pharyngitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acute and chronic tonsillitis and Bacterial infections.

Code Identity

ICD-10-CM Code
J03.00
Billable Status
Yes — Valid for Submission
Code Describes
Acute streptococcal tonsillitis, unspecified
Short Description
Acute streptococcal tonsillitis, unspecified
Same as the full description in the CMS dataset.
Parent Code
J03.0
Streptococcal tonsillitis

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ00-J06Acute upper respiratory infections
CategoryJ03Acute tonsillitis
This CodeJ03.00Acute streptococcal tonsillitis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute bacterial pharyngitis
  • Acute bacterial tonsillitis
  • Acute streptococcal pharyngitis
  • Acute tonsillitis caused by Streptococcus
  • Pneumococcal pharyngitis
  • Pneumococcal tonsillitis
  • Streptococcal sore throat
  • Streptococcal tonsillitis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR RSP004
Acute and chronic tonsillitis
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Streptococcal Infections

Strep is short for Streptococcus, a type of bacteria. There are several types. Two of them cause most of the strep infections in people: group A and group B.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert J03.00 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
034.0 Strep sore throat
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About J03.00Overview

What is the ICD-10 code for acute streptococcal tonsillitis, unspecified?

The ICD-10-CM code for acute streptococcal tonsillitis, unspecified is J03.00 (sometimes written as J0300). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is J03.00 (Streptococcal tonsillitis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report acute streptococcal tonsillitis, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does J03.00 group to?

When acute streptococcal 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 J03.00?

Under the General Equivalence Mappings, acute streptococcal tonsillitis, unspecified converts to ICD-9-CM 034.0 (strep sore throat). The mapping is approximate, so confirm the match fits the documentation.