2026 ICD-10-CM Diagnosis Code Z67.91Unspecified blood type, Rh negative

ICD-10-CM Codes›Z00–Z99›Z67›Z67

ICD-10-CM Z67.91
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z67.91 is a billable ICD-10-CM diagnosis code for unspecified blood type, Rh negative. 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 history of RhD negative. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified status.

Code Identity

ICD-10-CM Code
Z67.91
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified blood type, Rh negative
Short Description
Unspecified blood type, Rh negative
Same as the full description in the CMS dataset.
Parent Code
Z67.9
Unspecified blood type

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ67Blood type
CategoryZ67Blood type
This CodeZ67.91Unspecified blood type, Rh negative

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z67.91.

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

Z67.91 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.

  • History of RhD negative
  • Rh>mod< blood group phenotype
  • Rh>null< phenotype
  • Rr^-^ blood group phenotype
  • X^o^rX^o^r blood group phenotype

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.

    • Blood
      • type
        • Rh (positive)
          • negative

Clinical ClassificationClinical

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

CCSR FAC025
Other specified status
Default principal diagnosis: inpatient No · outpatient Yes

Clinical InformationClinical

  • ABO Blood Group|ABO Blood Type|ABO blood group system|ABO_Type

    a blood group system based on recognition of inherited differences in the h antigen as expressed on erythrocytes.

  • Blood Group A|A|Blood Type A

    a blood group indicating the presence on erythrocytes of only the a form of the h antigen.

  • Blood Group AB|AB|Blood Type AB

    a blood group indicating the presence on erythrocytes of both the a and b forms of the h antigen.

  • Blood Group B|B|Blood Type B

    a blood group indicating the presence on erythrocytes of only the b form of the h antigen.

  • Blood Group O|Blood Type O|O

    a blood group indicating the absence on erythrocytes of both the a and b forms of the h antigen.

  • Blood Group|Blood Type

    a classification of blood based on the presence or absence of inherited antigenic substances on the surface of erythrocytes.

  • Blood Type

    the specific reaction pattern of erythrocytes of an individual to the antisera of one blood group; e.g., the abo blood group consists of four major blood types: o, a, b, and ab. this classification depends on the presence or absence of two major antigens: a or b. type o occurs when neither is present and type ab when both are present. the blood type is the genetic phenotype of the individual for one blood group system and may be determined using different antisera available for testing.

  • Blood Type Determination

    a diagnostic test to classify the blood type of an individual. it is determined based on the presence or absence of certain antigens on the red blood cells surface.

  • Blood Typing Test|Blood Group Determination|Blood Group Typing|Blood Group Typing Test|Blood Type Determination|Blood Typing

    clinical laboratory tests that detect and identify the antigens expressed by red blood cells to determine a subject's blood type.

Patient EducationClinical

Blood

Your blood is made up of liquid and solids. The liquid part, called plasma, is made of water, salts, and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells, and platelets.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Z67.91 to ICD-9-CMHistory

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

ICD-9-CM
No Map There is no ICD-9 equivalent for this code.

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 Z67.91Overview

Is Z67.91 (Unspecified blood type) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified blood type, Rh negative on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z67.91 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because unspecified blood type, Rh negative describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z67.91 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 unspecified blood type, Rh negative on inpatient claims.