O9A.111 Malignant neoplasm complicating pregnancy, first trimester

Billable ICD-10-CM code, FY2026.

Applies from O9A.1 Malignant neoplasm complicating pregnancy, childbirth and the puerperium

Applicable to

• Conditions in C00-C96

Excludes2 (not included here)

• maternal care for benign tumor of corpus uteri (O34.1-)
• maternal care for benign tumor of cervix (O34.4-)

Use additional code

• code to identify neoplasm

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 648.91 Other current conditions classifiable elsewhere of mother, delivered, with or without mention of antepartum condition (approximate)
• 648.93 Other current conditions classifiable elsewhere of mother, antepartum condition or complication (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 O9A.111

Back-references to O9A.1

• Type 2 Excludes: O34.1 Maternal care for benign tumor of corpus uteri ("maternal care for malignant neoplasm of uterus (O9A.1-)")
• Type 2 Excludes: O99.8 Other specified diseases and conditions complicating pregnancy, childbirth and the puerperium ("malignant neoplasm complicating pregnancy, childbirth and the puerperium (O9A.1-)")

Back-references to O9A

• Type 1 Excludes: Z33.1 Pregnant state, incidental ("complications of pregnancy (O00-O9A)")
• Type 1 Excludes: Z34 Encounter for supervision of normal pregnancy ("any complication of pregnancy (O00-O9A)")
• Code First: Z3A Weeks of gestation ("obstetric condition or encounter for delivery (O09-O60, O80-O82, O94-O9A)")

Nearby codes

• O9A Maternal malignant neoplasms, traumatic injuries and abuse classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
• O9A.1 Malignant neoplasm complicating pregnancy, childbirth and the puerperium
• O9A.11 Malignant neoplasm complicating pregnancy
• O9A.111 Malignant neoplasm complicating pregnancy, first trimester (this code)
• O9A.112 Malignant neoplasm complicating pregnancy, second trimester
• O9A.113 Malignant neoplasm complicating pregnancy, third trimester
• O9A.119 Malignant neoplasm complicating pregnancy, unspecified trimester
• O9A.12 Malignant neoplasm complicating childbirth
• O9A.13 Malignant neoplasm complicating the puerperium