MCMCB Pro
Z22.321

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

Billable / specific codeICD-10-CMPOA exempt

Z22.321 is a billable, specific ICD-10-CM code for carrier or suspected carrier of methicillin susceptible staphylococcus aureus. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • MSSA colonization

Risk adjustment

Z22.321 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

Z22.321 is named in 1 Medicare coverage policy 0 listing it as supporting medical necessity, and 1 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52379Billing and Coding: CPT Code 87641 (Infectious agent detection by nucleic acid (DNA or RNA); Staphylococcus aureus, methicillin resistant, amplified probe technique)not covered

How Z22.321 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to Z22.321.

  • Carrier ofstaphylococci(Methicillin susceptible)
  • ColonizationMSSA(Methicillin susceptible Staphylococcus aureus)
  • Carrier ofbacterial disease NECstaphylococcal(Methicillin susceptible)
  • Positiveculturenosestaphylococcus(Methicillin susceptible)

Related codes at this level

Codes that share Z22.32. If Z22.321 is not quite right, the correct code is usually one of these.

Questions about Z22.321

Is Z22.321 a billable ICD-10-CM code?
Yes. Z22.321 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does Z22.321 sit in the tabular list?
Factors influencing health status and contact with health services (Z00-Z99), in the block Persons with potential health hazards related to communicable diseases (Z20-Z29).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.