2026 ICD-10-CM Diagnosis Code K11.21Acute sialoadenitis
ICD-10-CM Codes›K00–K95›K00-K14›K11
- Billable — Valid for Submission
- Not Chronic
K11.21 is a billable ICD-10-CM diagnosis code for acute sialoadenitis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 154 through 156. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Any dental condition including traumatic injury, Diseases of mouth; excluding dental, and Nontraumatic dental conditions.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute bacterial sialadenitis
- Acute on chronic sialoadenitis
- Acute sialoadenitis
- Acute viral sialadenitis
- Chronic sialadenitis
- Infective sialoadenitis
- Injury of salivary apparatus
- Injury of salivary gland
- Sialoadenitis of minor salivary gland
- Subacute necrotizing sialadenitis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Type 1 Excludes
- acute recurrent sialoadenitis K11.22
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Sialoadenitis (any gland) (periodic) (suppurative) - K11.20
- acute - K11.21
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Sialoadenitis(any gland) (periodic) (suppurative)
- acute
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Salivary Gland Disorders
Your salivary glands are in your mouth. You have three pairs of major salivary glands and hundreds of small (minor) glands. They make saliva (spit) and empty it into your mouth through openings called ducts. Saliva makes your food moist, which helps you chew and swallow. It helps you digest your food.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert K11.21 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About K11.21Overview
Is K11.21 (Sialoadenitis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report acute sialoadenitis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does K11.21 group to?
When acute sialoadenitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 154, 155, 156, with relative weights from 0.6911 to 1.5635 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of K11.21?
Under the General Equivalence Mappings, acute sialoadenitis converts to ICD-9-CM 527.2 (sialoadenitis). 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.
