2026 ICD-10-CM Diagnosis Code Z22.321Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus

ICD-10-CM Codes›Z00–Z99›Z20-Z29›Z22

ICD-10-CM Z22.321
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z22.321 is a billable ICD-10-CM diagnosis code for carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. Coders also document this condition as carrier of methicillin susceptible Staphylococcus aureus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Carrier status.

Code Identity

ICD-10-CM Code
Z22.321
Billable Status
Yes — Valid for Submission
Code Describes
Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus
Short Description
Carrier or suspected carrier of methicillin suscep staph
Parent Code
Z22.32
Carrier of bacterial disease due to staphylococci

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ20-Z29Persons with potential health hazards related to communicable diseases
CategoryZ22Carrier of infectious disease
This CodeZ22.321Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z22.321.

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.

Present on Admission (POA)Billing

Z22.321 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carrier of methicillin susceptible Staphylococcus aureus
  • Chronic colonization of respiratory tract caused by Staphylococcus aureus
  • Staphylococcus carrier
  • Suspected carrier of methicillin susceptible staphylococcus aureus

Tabular List NotesGuidance

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

Inclusion Terms

  • MSSA colonization

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.

    • Carrier(suspected) of
      • bacterial disease NEC
        • staphylococcal (Methicillin susceptible)
    • Carrier(suspected) of
      • staphylococci (Methicillin susceptible)
    • Colonization
      • MSSA (Methicillin susceptible Staphylococcus aureus)
    • Positive
      • culture (nonspecific)
        • nose
          • staphylococcus (Methicillin susceptible)

Clinical ClassificationClinical

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

CCSR FAC024
Carrier status
Default principal diagnosis: inpatient No · outpatient Yes

Convert Z22.321 to ICD-9-CMHistory

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

ICD-9-CM
V02.53 Meth susc Staph carrier
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 Z22.321Overview

Is Z22.321 (Carrier of bacterial disease due to staphylococci) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z22.321 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z22.321 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus on inpatient claims.

What is the ICD-9 equivalent of Z22.321?

Under the General Equivalence Mappings, carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus converts to ICD-9-CM V02.53 (meth susc Staph carrier). The mapping is a direct match.