2027 ICD-10-CM Diagnosis Code O33.2Maternal care for disproportion due to inlet contraction of pelvis

ICD-10-CM Codes›O00-O9A›O30-O48›O33

ICD-10-CM O33.2
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

O33.2 is a billable ICD-10-CM diagnosis code for maternal care for disproportion due to inlet contraction of pelvis. 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. The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). Coders also document this condition as contracted pelvis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Malposition, disproportion or other labor complications.

Code Identity

ICD-10-CM Code
O33.2
Billable Status
Yes — Valid for Submission
Code Describes
Maternal care for disproportion due to inlet contraction of pelvis
Short Description
Maternal care for disproprtn due to inlet contrctn of pelvis
Parent Code
O33
Maternal care for disproportion

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO30-O48Maternal care related to the fetus and amniotic cavity and possible delivery problems
CategoryO33Maternal care for disproportion
This CodeO33.2Maternal care for disproportion due to inlet contraction of pelvis

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O33.2.

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).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Contracted pelvis
  • Inlet contraction of pelvis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to O33.2: its own notes plus those printed at O33 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 O33 Maternal care for disproportion applies to 40 codes
  • the listed conditions as a reason for observation, hospitalization or other obstetric care of the mother, or for cesarean delivery before onset of labor

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Maternal care for disproportion due to inlet contraction (pelvis) causing disproportion

Excludes1

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

From O33 Maternal care for disproportion applies to 40 codes
  • disproportion with obstructed labor (O65-O66)
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 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

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name O33.2, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming O33.2: they are not reported together with it, unless the two conditions are unrelated.

  • M95.5 Acquired deformity of pelvis
    maternal care for known or suspected disproportion (O33.-) names O33.-, which includes this code

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.

CCSR PRG024
Malposition, disproportion or other labor complications
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Childbirth Problems

Childbirth is the process of giving birth to a baby. It includes labor and delivery. Usually everything goes well, but problems can happen. They may cause a risk to the mother, baby, or both. Some of the more common childbirth problems include:

Read the full article at MedlinePlus

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

Convert O33.2 to ICD-9-CMHistory

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

ICD-9-CM
653.21 Inlet contraction-deliv
Approximate The match is approximate rather than exact.
ICD-9-CM
653.23 Inlet contract-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 O33.2Overview

What is the ICD-10 code for maternal care for disproportion due to inlet contraction of pelvis?

The ICD-10-CM code for maternal care for disproportion due to inlet contraction of pelvis is O33.2 (sometimes written as O332). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is O33.2 (Maternal care for disproportion) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report maternal care for disproportion due to inlet contraction of pelvis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does O33.2 group to?

When maternal care for disproportion due to inlet contraction of pelvis 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.

Who can O33.2 be reported for?

The Medicare Code Editor checks maternal care for disproportion due to inlet contraction of pelvis against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.

What is the ICD-9 equivalent of O33.2?

Under the General Equivalence Mappings, maternal care for disproportion due to inlet contraction of pelvis converts to ICD-9-CM 653.21 (inlet contraction-deliv) and 653.23 (inlet contract-antepart). The mapping is approximate, so confirm the match fits the documentation.