2026 ICD-10-CM Diagnosis Code J01.00Acute maxillary sinusitis, unspecified

ICD-10-CM Codes›J00–J99›J00-J06›J01

ICD-10-CM J01.00
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J01.00 is a billable ICD-10-CM diagnosis code for acute maxillary sinusitis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 152 through 153. Coders also document this condition as abscess of nasal sinus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sinusitis.

Code Identity

ICD-10-CM Code
J01.00
Billable Status
Yes — Valid for Submission
Code Describes
Acute maxillary sinusitis, unspecified
Short Description
Acute maxillary sinusitis, unspecified
Same as the full description in the CMS dataset.
Parent Code
J01.0
Acute maxillary sinusitis

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ00-J06Acute upper respiratory infections
CategoryJ01Acute sinusitis
This CodeJ01.00Acute maxillary sinusitis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abscess of nasal sinus
  • Acute abscess of maxillary sinus
  • Acute abscess of nasal sinus
  • Acute empyema of maxillary sinus
  • Acute empyema of nasal sinus
  • Acute maxillary sinusitis
  • Acute suppuration of maxillary sinus
  • Acute suppuration of nasal sinus
  • Empyema of nasal sinus

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Antritis
      • maxilla
        • acute
    • Sinusitis(accessory) (chronic) (hyperplastic) (nasal) (nonpurulent) (purulent)
      • acute
        • maxillary
    • Sinusitis(accessory) (chronic) (hyperplastic) (nasal) (nonpurulent) (purulent)
      • maxillary
        • acute

Clinical ClassificationClinical

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

CCSR RSP001
Sinusitis
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Chronic Maxillary Sinusitis

    inflammation of the maxillary sinus that typically lasts beyond eight weeks. it is caused by infections, allergies, and the presence of sinus polyps or a deviated septum. signs and symptoms include headache, nasal discharge, swelling in the face, dizziness, and breathing difficulties.

  • Maxillary Sinusitis

    an acute or chronic inflammatory process affecting the mucous membrane of the maxillary sinus.

Patient EducationClinical

Sinusitis

Sinusitis means your sinuses are inflamed. The cause can be an infection or another problem. Your sinuses are hollow air spaces within the bones surrounding the nose. They produce mucus, which drains into the nose. If your nose is swollen, this can block the sinuses and cause pain.

Read the full article at MedlinePlus

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

Convert J01.00 to ICD-9-CMHistory

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

ICD-9-CM
461.0 Ac maxillary sinusitis
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 J01.00Overview

Is J01.00 (Acute maxillary sinusitis) a billable code?

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

What MS-DRG does J01.00 group to?

When acute maxillary sinusitis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 152, 153, with relative weights from 0.7382 to 1.1822 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of J01.00?

Under the General Equivalence Mappings, acute maxillary sinusitis, unspecified converts to ICD-9-CM 461.0 (ac maxillary sinusitis). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.