2027 ICD-10-CM Diagnosis Code Z22.2Carrier of diphtheria
Z22.2 is a billable ICD-10-CM diagnosis code for carrier of diphtheria. 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 diphtheria carrier. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Carrier status.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for Z22.2.
Present on Admission (POA)Billing
Z22.2 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.
- Diphtheria carrier
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to Z22.2: 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.
- colonization status
- suspected carrier
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.
Notes
General instructions on how these codes are used.
- 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 Z22.2, its category, or a range that includes it.
Excludes1 8
These codes carry an Excludes1 note naming Z22.2: they are not reported together with it, unless the two conditions are unrelated.
- R82.7 Abnormal findings on microbiological examination of urinecolonization status (Z22.-) names Z22.-, which includes this code
- R83.5 Abnormal microbiological findings in cerebrospinal fluidcolonization status (Z22.-) names Z22.-, which includes this code
- R84.5 Abnormal microbiological findings in specimens from respiratory organs and thoraxcolonization status (Z22.-) names Z22.-, which includes this code
- R85.5 Abnormal microbiological findings in specimens from digestive organs and abdominal cavitycolonization status (Z22.-) names Z22.-, which includes this code
- R86.5 Abnormal microbiological findings in specimens from male genital organscolonization status (Z22.-) names Z22.-, which includes this code
- R87.5 Abnormal microbiological findings in specimens from female genital organscolonization status (Z22.-) names Z22.-, which includes this code
- R89.5 Abnormal microbiological findings in specimens from other organs, systems and tissuescolonization status (Z22.-) names Z22.-, which includes this code
- Z20 Contact with and (suspected) exposure to communicable diseasescarrier of infectious disease (Z22.-) names Z22.-, which includes this code
Excludes2 1
These codes carry an Excludes2 note naming Z22.2: 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 diseasescarrier 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 Z22.2 is one of the codes named.
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.
Patient EducationClinical
Diphtheria
Diphtheria is a serious bacterial infection. You can catch it from a person who has the infection and coughs or sneezes. You can also get infected by coming in contact with an object, such as a toy, that has bacteria on it.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert Z22.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About Z22.2Overview
What is the ICD-10 code for carrier of diphtheria?
The ICD-10-CM code for carrier of diphtheria is Z22.2 (sometimes written as Z222). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is Z22.2 (Carrier of infectious disease) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report carrier of diphtheria on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does Z22.2 group to?
On inpatient claims, carrier of diphtheria 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 Z22.2 be a principal diagnosis?
No. The Medicare Code Editor rejects this code as a principal diagnosis because carrier of diphtheria describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.
Is Z22.2 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 of diphtheria 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.
