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

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Maternal care for disproportion due to pelvic deformity causing disproportion NOS

Applies from O33 Maternal care for disproportion

Includes

• 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 (never code together)

• disproportion with obstructed labor (O65-O66)

MS-DRG index

Defines the logic of DRG(s) 817-819 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 648.71 Bone and joint disorders of back, pelvis, and lower limbs of mother, delivered, with or without mention of antepartum condition (approximate)
• 648.72 Bone and joint disorders of back, pelvis, and lower limbs of mother, delivered, with mention of postpartum complication (approximate)
• 653.01 Major abnormality of bony pelvis, not further specified, delivered, with or without mention of antepartum condition (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Maternity diagnoses (age 9 through 64): Age conflict edit. These diagnoses are clinically expected only in patients age 9 through 64.

Code annotations containing back-references to O33.0

Back-references to O33

• Type 1 Excludes: M95.5 Acquired deformity of pelvis ("maternal care for known or suspected disproportion (O33.-)")

Diagnosis Index entries for O33.0

• Anthropoid pelvis › with disproportion (fetopelvic)
• Cretin, cretinism (congenital) (endemic) (nongoitrous) (sporadic) › pelvis › with disproportion (fetopelvic)
• Deformity › pelvis, pelvic (acquired) (bony) › with disproportion (fetopelvic)
• Delivery (childbirth) (labor) › cesarean (for) › abnormal › pelvis (bony) (deformity) (major) NEC with disproportion (fetopelvic)
• Delivery (childbirth) (labor) › cesarean (for) › deformity (acquired) (congenital) › pelvis (bony) NEC
• Flat › pelvis › with disproportion (fetopelvic)
• Nägele's pelvis › with disproportion (fetopelvic)
• Pithecoid pelvis › with disproportion (fetopelvic)
• Platypelloid pelvis › with disproportion (fetopelvic)
• Pregnancy (single) (uterine) › complicated by (care of) (management affected by) › abnormal, abnormality › pelvis (bony) (major) NEC
• Prominence, prominent › ischial spine or sacral promontory with disproportion (fetopelvic)
• Rachitic › pelvis (late effect) (sequelae) › with disproportion (fetopelvic)
• Robert's pelvis › with disproportion (fetopelvic)
• Scoliotic pelvis › with disproportion (fetopelvic)
• Spondylolisthesis (acquired) (degenerative) › with disproportion (fetopelvic)
• Spondylolysis (acquired) › lumbosacral region › with disproportion (fetopelvic)
• Spondylosis › with › disproportion (fetopelvic)
• Tipping › pelvis › with disproportion (fetopelvic)

Nearby codes

• O33 Maternal care for disproportion
• O33.0 Maternal care for disproportion due to deformity of maternal pelvic bones (this code)
• 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 pelvis
• 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