2027 ICD-10-CM Diagnosis Code O33.5XX0Maternal care for disproportion due to unusually large fetus, not applicable or unspecified
O33.5XX0 is a billable ICD-10-CM diagnosis code for maternal care for disproportion due to unusually large fetus, not applicable or unspecified. The 7th character 0 shows this applies to a single gestation, or that the affected fetus is not identified. 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 fetal disproportion due to large fetus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Malposition, disproportion or other labor complications.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O33.5XX0.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Fetal disproportion due to large fetus
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to O33.5XX0: its own notes plus those printed at O33.5, 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.
- the listed conditions as a reason for observation, hospitalization or other obstetric care of the mother, or for cesarean delivery before onset of labor
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- 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.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- 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.
- 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.
- One of the following 7th characters is to be assigned to code O33.5. 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 code O33.5 with a 7th character of 1 through 9.
- 0not applicable or unspecified this code
- 1fetus 1
- 2fetus 2
- 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 O33.5XX0, its category, or a range that includes it.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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
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Convert O33.5XX0 to ICD-9-CMHistory
Code HistoryHistory
Questions About O33.5XX0Overview
Is O33.5XX0 (Maternal care for disproportion due to unusually large fetus) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report maternal care for disproportion due to unusually large fetus, not applicable or unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character 0 in O33.5XX0 mean?
The final character 0 shows the maternal care for disproportion due to unusually large fetus applies to a single gestation, or that the affected fetus cannot be identified.
What MS-DRG does O33.5XX0 group to?
When maternal care for disproportion due to unusually large fetus, not applicable or unspecified 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 O33.5XX0 be reported for?
The Medicare Code Editor checks maternal care for disproportion due to unusually large fetus, not applicable or unspecified 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 O33.5XX0?
Under the General Equivalence Mappings, maternal care for disproportion due to unusually large fetus, not applicable or unspecified converts to ICD-9-CM 653.51 (fetal disprop NOS-deliv) and 653.53 (fetal dispro NOS-antepar). The mapping is approximate, so confirm the match fits the documentation.
