Z22.321 Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus

The ICD-10-CM code for Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus is Z22.321 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

21: Factors influencing health status and contact with health services (Z00-Z99)

Section

Z20-Z29: Persons with potential health hazards related to communicable diseases (Z20-Z29)

Category Z22

26 codes (20 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to Z22.321:

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

Inclusion Terms

• MSSA colonization

U.S. Hospital Utilization

• An estimated 5,715 U.S. inpatient stays in 2023 included Z22.321 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

MSSA/MRSA colonization (Z22.321/Z22.322)

(c) Methicillin susceptible Staphylococcus aureus (MSSA) and MRSA colonization The condition or state of being colonized or carrying MSSA or MRSA is called colonization or carriage, while an individual person is described as being colonized or being a carrier. Colonization means that MSSA or MSRA is present on or in the body without necessarily causing illness. A positive MRSA colonization test might be documented by the provider as “MRSA screen positive” or “MRSA nasal swab positive”. Assign code Z22.322, Carrier or suspected carrier of Methicillin resistant Staphylococcus aureus, for patients documented as having MRSA colonization. Assign code Z22.321, Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus, for patients documented as having MSSA colonization. Colonization is not necessarily indicative of a disease process or

Used with any code in range A00.0-T88.9, Z00-Z99

1) Used with any code in the range of A00.0-T88.9, Z00-Z99 An external cause code may be used with any code in the range of A00.0-T88.9, Z00-Z99, classification that represents a health condition due to an external cause. Though they are most applicable to injuries, they are also valid for use with such things as infections or diseases due to an external source, and other health conditions, such as a heart attack that occurs during strenuous physical activity.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)

Cite This Page

Reference Z22.321 with the canonical source and edition:

Z22.321 — Carrier or suspected carrier of Methicillin susceptible Staphylococcus aureus. ICD-10 Coding Pro (ICD-10-CM FY2026). https://icd10codingpro.com/codes/Z22.321

Canonical URL: https://icd10codingpro.com/codes/Z22.321