2027 ICD-10-CM Diagnosis Code O36.0122Maternal care for anti-D [Rh] antibodies, second trimester, fetus 2

ICD-10-CM Codes›O00-O9A›O30-O48›O36

ICD-10-CM O36.0122
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

O36.0122 is a billable ICD-10-CM diagnosis code for maternal care for anti-D [Rh] antibodies, second trimester, fetus 2. The 7th character 2 identifies fetus 2 in a multiple gestation pregnancy. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 817 through 819, 831 through 833. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 42 closely related codes. The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Maternal care related to fetal conditions.

Code Identity

ICD-10-CM Code
O36.0122
Billable Status
Yes — Valid for Submission
Code Describes
Maternal care for anti-D [Rh] antibodies, second trimester, fetus 2
Short Description
Maternal care for anti-D antibodies, second tri, fetus 2
Parent Code
O36.012
Maternal care for anti-D [Rh] antibodies, second trimester

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO30-O48Maternal care related to the fetus and amniotic cavity and possible delivery problems
CategoryO36Maternal care for other fetal problems
This CodeO36.0122Maternal care for anti-D [Rh] antibodies, second trimester, fetus 2

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O36.0122.

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).

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to O36.0122: its own notes plus those printed at O36 and Chapter 15. 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.

From O36 Maternal care for other fetal problems applies to 399 codes
  • the listed conditions in the fetus as a reason for hospitalization or other obstetric care of the mother, or for termination of pregnancy

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From O36 Maternal care for other fetal problems applies to 399 codes
  • encounter for suspected maternal and fetal conditions ruled out (Z03.7-)
  • placental transfusion syndromes (O43.0-)
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • supervision of normal pregnancy (Z34.-)

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.

From O36 Maternal care for other fetal problems applies to 399 codes
  • labor and delivery complicated by fetal stress (O77.-)
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • mental and behavioral disorders associated with the puerperium (F53.-)
  • obstetrical tetanus (A34)
  • postpartum necrosis of pituitary gland (E23.0)
  • puerperal osteomalacia (M83.0)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.

Notes

General instructions on how these codes are used.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
  • Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
  • Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
  • 1st trimester- less than 14 weeks 0 days
  • 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
  • 3rd trimester- 28 weeks 0 days until delivery

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From O36 Maternal care for other fetal problems applies to 399 codes
  • One of the following 7th characters is to be assigned to each code under category O36. 7th character 0 is for single gestations and multiple gestations where the fetus is unspecified. 7th characters 1 through 9 are for cases of multiple gestations to identify the fetus for which the code applies. The appropriate code from category O30, Multiple gestation, must also be assigned when assigning a code from category O36 that has a 7th character of 1 through 9.
Values for category O36 Fetus Identification
  • 0not applicable or unspecified
  • 1fetus 1
  • 2fetus 2 this code
  • 3fetus 3
  • 4fetus 4
  • 5fetus 5
  • 9other fetus

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name O36.0122, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming O36.0122: they are not reported together with it, unless the two conditions are unrelated.

  • O36.2 Maternal care for hydrops fetalis
    hydrops fetalis associated with rhesus isoimmunization (O36.0-) names O36.0-, which includes this code
  • Z03.7 Encounter for suspected maternal and fetal conditions ruled out
    known or suspected fetal anomalies affecting management of mother, not ruled out (O26.-, O35.-, O36.-, O40.-, O41.-) names O36.-, which includes this code

Clinical ClassificationClinical

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

CCSR PRG013
Maternal care related to fetal conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Rh Incompatibility

There are four major blood types: A, B, O, and AB. The types are based on substances found on your blood cells. Your blood type also has a positive or negative sign. This is called Rh factor, which is a protein. If your blood cells have this protein, you are Rh-positive. If you don't, you are Rh-negative.

The full article covers:

  • What is the Rh factor?
  • What is Rh incompatibility?
  • How is Rh incompatibility diagnosed?
  • How is Rh incompatibility treated?
  • Can Rh incompatibility be prevented?

Read the full article at MedlinePlus

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

Convert O36.0122 to ICD-9-CMHistory

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

ICD-9-CM
656.11 Rh isoimmunizat-deliver
Approximate The match is approximate rather than exact.
ICD-9-CM
656.13 Rh isoimmunizat-antepart
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About O36.0122Overview

What is the ICD-10 code for maternal care for anti-D [Rh] antibodies, second trimester, fetus 2?

The ICD-10-CM code for maternal care for anti-D [Rh] antibodies, second trimester, fetus 2 is O36.0122 (sometimes written as O360122). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is O36.0122 (Maternal care for anti-D [Rh] antibodies, second trimester) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report maternal care for anti-D [Rh] antibodies, second trimester, fetus 2 on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character 2 in O36.0122 mean?

The final character 2 identifies the fetus in a multiple gestation pregnancy: this code reports maternal care for anti-D [Rh] antibodies, second trimester for fetus 2.

What MS-DRG does O36.0122 group to?

When maternal care for anti-D [Rh] antibodies, second trimester, fetus 2 is the principal diagnosis on an inpatient stay, it groups to MS-DRG 833, 832, 831, 819, 818, 817, with relative weights from 0.5000 to 1.7586 depending on complications. Higher weights mean higher Medicare reimbursement.

Is O36.0122 a CC or MCC?

CMS lists O36.0122 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 42 closely related codes in its exclusion list.