2026 ICD-10-CM Diagnosis Code Z36.5Encounter for antenatal screening for isoimmunization

ICD-10-CM Codes›Z00–Z99›Z30-Z39›Z36

ICD-10-CM Z36.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z36.5 is a billable ICD-10-CM diagnosis code for encounter for antenatal screening for isoimmunization. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64) and exempt from POA reporting. Coders also document this condition as Anti-D not detected by screening. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Antenatal screening.

Code Identity

ICD-10-CM Code
Z36.5
Billable Status
Yes — Valid for Submission
Code Describes
Encounter for antenatal screening for isoimmunization
Short Description
Encounter for antenatal screening for isoimmunization
Same as the full description in the CMS dataset.
Parent Code
Z36
Encounter for antenatal screening of mother

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ30-Z39Persons encountering health services in circumstances related to reproduction
CategoryZ36Encounter for antenatal screening of mother
This CodeZ36.5Encounter for antenatal screening for isoimmunization

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z36.5.

Maternity diagnoses
The Medicare Code Editor detects inconsistencies in maternity cases by checking a patient's age and any diagnosis on the patient's record. The maternity code edits apply to patients age ange is 9–64 years inclusive (e.g., diabetes in pregnancy, antepartum pulmonary complication).

Present on Admission (POA)Billing

Z36.5 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.

  • Anti-D not detected by screening

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.

    • Encounter(with health service) (for)
      • antenatal screening
        • isoimmunization

Clinical ClassificationClinical

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

CCSR PRG001
Antenatal screening
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert Z36.5 to ICD-9-CMHistory

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

ICD-9-CM
V28.5 Screen-isoimmunization
Exact Match The mapping is direct, with no qualifiers.

Code History & ChangesHistory

Replacement Z36.5 replaces the following previously assigned code(s):

  • Z36 - Encounter for antenatal screening of mother
FY 2018AddedAdded to the ICD-10-CM code setEffective October 1, 2017.
FY 2019–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z36.5Overview

Is Z36.5 (Encounter for antenatal screening of mother) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report encounter for antenatal screening for isoimmunization on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Who can Z36.5 be reported for?

The Medicare Code Editor checks encounter for antenatal screening for isoimmunization against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.

Is Z36.5 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 encounter for antenatal screening for isoimmunization on inpatient claims.

What is the ICD-9 equivalent of Z36.5?

Under the General Equivalence Mappings, encounter for antenatal screening for isoimmunization converts to ICD-9-CM V28.5 (screen-isoimmunization). The mapping is a direct match.