2026 ICD-10-CM Diagnosis Code B97.21SARS-associated coronavirus as the cause of diseases classified elsewhere

ICD-10-CM Codes›A00–B99›B95-B97›B97

ICD-10-CM B97.21
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B97.21 is a billable ICD-10-CM diagnosis code for SARS-associated coronavirus as the cause of diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 865 through 866. The code is not accepted as a principal diagnosis by the Medicare Code Editor. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Viral infection.

Code Identity

ICD-10-CM Code
B97.21
Billable Status
Yes — Valid for Submission
Code Describes
SARS-associated coronavirus as the cause of diseases classified elsewhere
Short Description
SARS-associated coronavirus causing diseases classd elswhr
Parent Code
B97.2
Coronavirus as the cause of diseases classified elsewhere

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB95-B97Bacterial and viral infectious agents
CategoryB97Viral agents as the cause of diseases classified elsewhere
This CodeB97.21SARS-associated coronavirus as the cause of diseases classified elsewhere

Code EditsBilling

Medicare Code Editor checks that affect claim validity for B97.21.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • pneumonia due to SARS-associated coronavirus J12.81

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.

    • Coronavirus(infection)
      • SARS-associated
    • Infection, infected, infective(opportunistic)
      • coronavirus NEC
        • severe acute respiratory syndrome (SARS associated)
    • Infection, infected, infective(opportunistic)
      • virus, viral NOS
        • as cause of disease classified elsewhere
          • coronavirus
            • SARS-associated

Clinical ClassificationClinical

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

CCSR INF008
Viral infection
Default principal diagnosis: inpatient No · outpatient No

Convert B97.21 to ICD-9-CMHistory

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

ICD-9-CM
079.82 SARS assoc coronavirus
Exact Match The mapping is direct, with no qualifiers.

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 B97.21Overview

Is B97.21 (Coronavirus as the cause of diseases classified elsewhere) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report SARS-associated coronavirus as the cause of diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does B97.21 group to?

On inpatient claims, SARS-associated coronavirus as the cause of diseases classified elsewhere maps to MS-DRG 865, 866, with relative weights from 0.8696 to 1.4983 depending on complications. Higher weights mean higher Medicare reimbursement.

Can B97.21 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because SARS-associated coronavirus as the cause of diseases classified elsewhere describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

What is the ICD-9 equivalent of B97.21?

Under the General Equivalence Mappings, SARS-associated coronavirus as the cause of diseases classified elsewhere converts to ICD-9-CM 079.82 (SARS assoc coronavirus). The mapping is a direct match.

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.