O33.0Maternal care for disproportion due to deformity of maternal pelvic bones

O33.0 is the ICD-10-CM diagnosis code for maternal care for disproportion due to deformity of maternal pelvic bones. It belongs to category O33 (maternal care for disproportion), block O30-O48 (maternal care related to the fetus and amniotic cavity and possible delivery problems) and chapter 15 (pregnancy, childbirth and the puerperium). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within O33 (maternal care for disproportion), O33.0 is specifically for maternal care for disproportion due to deformity of maternal pelvic bones. Related codes cover due to generally contracted pelvis (O33.1), due to inlet contraction of pelvis (O33.2), due to outlet contraction of pelvis (O33.3), of mixed maternal and fetal origin (O33.4), due to unusually large fetus (O33.5), due to hydrocephalic fetus (O33.6), due to other fetal deformities (O33.7), of other origin (O33.8) and 1 more.

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 817 (Other Antepartum Diagnoses with O.R. Procedures with MCC, relative weight 2.0534), DRG 818 (Other Antepartum Diagnoses with O.R. Procedures with CC, relative weight 1.2942), DRG 819 (Other Antepartum Diagnoses with O.R. Procedures without CC/MCC, relative weight 0.7739), DRG 831 (Other Antepartum Diagnoses without O.R. Procedures with MCC, relative weight 1.1558), DRG 832 (Other Antepartum Diagnoses without O.R. Procedures with CC, relative weight 0.7585) and DRG 833 (Other Antepartum Diagnoses without O.R. Procedures without CC/MCC, relative weight 0.5002), in MDC 14 (Pregnancy, Childbirth and the Puerperium), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

The Medicare Code Editor treats this as a maternity diagnosis, expected only for patients age 9 through 64.

It is on the CMS list of diagnoses consistent only with female patients (the sex-conflict edit itself was retired in FY2025).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 648.71 (bone and joint disorders of back, pelvis, and lower limbs of mother, delivered, with or without mention of antepartum condition), 648.72 (bone and joint disorders of back, pelvis, and lower limbs of mother, delivered, with mention of postpartum complication) and 653.01 (major abnormality of bony pelvis, not further specified, delivered, with or without mention of antepartum condition).