2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 951. 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 the other POA exempt codes in Persons with potential health hazards related to communicable diseases (Z20-Z29).

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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Z22.321: its own notes plus those printed at Z22 and Chapter 21. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Z22 Carrier of infectious disease applies to 20 codes
  • colonization status
  • suspected carrier

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • MSSA colonization

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Z22 Carrier of infectious disease applies to 20 codes
  • carrier of viral hepatitis (B18.-)

Notes

General instructions on how these codes are used.

From Chapter 21 (Z00-Z99) Factors influencing health status and contact with health services applies to 1,425 codes
  • Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
  • (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
  • (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name Z22.321, its category, or a range that includes it.

Excludes1 8

These codes carry an Excludes1 note naming Z22.321: they are not reported together with it, unless the two conditions are unrelated.

  • R82.7 Abnormal findings on microbiological examination of urine
    colonization status (Z22.-) names Z22.-, which includes this code
  • R83.5 Abnormal microbiological findings in cerebrospinal fluid
    colonization status (Z22.-) names Z22.-, which includes this code
  • R84.5 Abnormal microbiological findings in specimens from respiratory organs and thorax
    colonization status (Z22.-) names Z22.-, which includes this code
  • R85.5 Abnormal microbiological findings in specimens from digestive organs and abdominal cavity
    colonization status (Z22.-) names Z22.-, which includes this code
  • R86.5 Abnormal microbiological findings in specimens from male genital organs
    colonization status (Z22.-) names Z22.-, which includes this code
  • R87.5 Abnormal microbiological findings in specimens from female genital organs
    colonization status (Z22.-) names Z22.-, which includes this code
  • R89.5 Abnormal microbiological findings in specimens from other organs, systems and tissues
    colonization status (Z22.-) names Z22.-, which includes this code
  • Z20 Contact with and (suspected) exposure to communicable diseases
    carrier of infectious disease (Z22.-) names Z22.-, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming Z22.321: its condition is not part of those codes, and both may be reported when the patient has both.

  • Chapter 1 (A00-B99) Certain infectious and parasitic diseases
    carrier or suspected carrier of infectious disease (Z22.-) names Z22.-, which includes this code

Use Additional Code 1

These codes say to use an additional code from the note, and Z22.321 is one of the codes named.

  • O99.83 Other infection carrier state complicating pregnancy, childbirth and the puerperium
    code to identify the carrier state (Z22.-) names Z22.-, which includes this code

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 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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does Z22.321 group to?

On inpatient claims, carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus maps to MS-DRG 951 (other Factors Influencing Health Status), which carries a relative weight of 0.5574. Higher weights mean higher Medicare reimbursement.

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. The code appears in the Persons with potential health hazards related to communicable diseases (Z20-Z29) range of the CMS exempt list.

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.