Maternal care for disproportion (O33) ICD-10-CM
The O33 code range covers maternal care for disproportion with 46 ICD-10-CM diagnosis codes. 40 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give 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
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the O33 Range 46 codes · 40 billable
- O33 Maternal care for disproportionNon-billable
- O33.0 Maternal care for disproportion due to deformity of maternal pelvic bones
- O33.1 Maternal care for disproportion due to generally contracted pelvis
- O33.2 Maternal care for disproportion due to inlet contraction of pelvis
- O33.3 Maternal care for disproportion due to outlet contraction of pelvisNon-billable
- O33.3XX0 Maternal care for disproportion due to outlet contraction of pelvis, not applicable or unspecified
- O33.3XX1 Maternal care for disproportion due to outlet contraction of pelvis, fetus 1
- O33.3XX2 Maternal care for disproportion due to outlet contraction of pelvis, fetus 2
- O33.3XX3 Maternal care for disproportion due to outlet contraction of pelvis, fetus 3
- O33.3XX4 Maternal care for disproportion due to outlet contraction of pelvis, fetus 4
- O33.3XX5 Maternal care for disproportion due to outlet contraction of pelvis, fetus 5
- O33.3XX9 Maternal care for disproportion due to outlet contraction of pelvis, other fetus
- O33.4 Maternal care for disproportion of mixed maternal and fetal originNon-billable
- O33.4XX0 Maternal care for disproportion of mixed maternal and fetal origin, not applicable or unspecified
- O33.4XX1 Maternal care for disproportion of mixed maternal and fetal origin, fetus 1
- O33.4XX2 Maternal care for disproportion of mixed maternal and fetal origin, fetus 2
- O33.4XX3 Maternal care for disproportion of mixed maternal and fetal origin, fetus 3
- O33.4XX4 Maternal care for disproportion of mixed maternal and fetal origin, fetus 4
- O33.4XX5 Maternal care for disproportion of mixed maternal and fetal origin, fetus 5
- O33.4XX9 Maternal care for disproportion of mixed maternal and fetal origin, other fetus
- O33.5 Maternal care for disproportion due to unusually large fetusNon-billable
- O33.5XX0 Maternal care for disproportion due to unusually large fetus, not applicable or unspecified
- O33.5XX1 Maternal care for disproportion due to unusually large fetus, fetus 1
- O33.5XX2 Maternal care for disproportion due to unusually large fetus, fetus 2
- O33.5XX3 Maternal care for disproportion due to unusually large fetus, fetus 3
- O33.5XX4 Maternal care for disproportion due to unusually large fetus, fetus 4
- O33.5XX5 Maternal care for disproportion due to unusually large fetus, fetus 5
- O33.5XX9 Maternal care for disproportion due to unusually large fetus, other fetus
- O33.6 Maternal care for disproportion due to hydrocephalic fetusNon-billable
- O33.6XX0 Maternal care for disproportion due to hydrocephalic fetus, not applicable or unspecified
- O33.6XX1 Maternal care for disproportion due to hydrocephalic fetus, fetus 1
- O33.6XX2 Maternal care for disproportion due to hydrocephalic fetus, fetus 2
- O33.6XX3 Maternal care for disproportion due to hydrocephalic fetus, fetus 3
- O33.6XX4 Maternal care for disproportion due to hydrocephalic fetus, fetus 4
- O33.6XX5 Maternal care for disproportion due to hydrocephalic fetus, fetus 5
- O33.6XX9 Maternal care for disproportion due to hydrocephalic fetus, other fetus
- O33.7 Maternal care for disproportion due to other fetal deformitiesNon-billable
- O33.7XX0 Maternal care for disproportion due to other fetal deformities, not applicable or unspecified
- O33.7XX1 Maternal care for disproportion due to other fetal deformities, fetus 1
- O33.7XX2 Maternal care for disproportion due to other fetal deformities, fetus 2
- O33.7XX3 Maternal care for disproportion due to other fetal deformities, fetus 3
- O33.7XX4 Maternal care for disproportion due to other fetal deformities, fetus 4
- O33.7XX5 Maternal care for disproportion due to other fetal deformities, fetus 5
- O33.7XX9 Maternal care for disproportion due to other fetal deformities, other fetus
- O33.8 Maternal care for disproportion of other origin
- O33.9 Maternal care for disproportion, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the O33 range.
Cephalopelvic Disproportion
A condition in which the HEAD of the FETUS is larger than the mother's PELVIS through which the fetal head must pass during a vaginal delivery.
About the O33 Code Range
ICD-10 code section O33 covers maternal care for disproportion, addressing complications where there is a size mismatch between the fetus and the maternal pelvis that can affect labor and delivery. This includes specific conditions based on maternal pelvic deformities, contractions, or fetal size and shape abnormalities.
The codes in the O33 category specify different causes of this disproportion. For example, O33.0 is for disproportion due to deformity of the maternal pelvic bones, often referred to as "Disproportion - major pelvic abnormality" or "Pelvis not adequate for delivery." O33.1 and O33.2 denote generally contracted pelvis or inlet contraction of the pelvis, known variously as "Contracted pelvis" or "Pelvic disproportion." Variations also include outlet pelvic contractions (O33.3), mixed maternal and fetal causes (O33.4), and fetal factors like unusually large fetus (O33.5) or hydrocephalic fetus (O33.6). Other fetal deformities causing disproportion fall under O33.7, while unspecified causes and other origins are covered under O33.9 and O33.8. These codes help coders identify precise causes behind cephalopelvic disproportion, assisting in correct maternal care documentation and treatment planning.
Questions About This Page
How many billable codes are in the O33 range?
Of the 46 codes in this range, 40 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the O33 range classify?
The range classifies maternal care for disproportion. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
