2026 ICD-10-CM Diagnosis Code O9A.111Malignant neoplasm complicating pregnancy, first trimester

ICD-10-CM Codes›O00-O9A›O94-O9A›O9A

ICD-10-CM O9A.111
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O9A.111 is a billable ICD-10-CM diagnosis code for malignant neoplasm complicating pregnancy, first trimester. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) 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). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified complications in pregnancy.

Code Identity

ICD-10-CM Code
O9A.111
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm complicating pregnancy, first trimester
Short Description
Malignant neoplasm complicating pregnancy, first trimester
Same as the full description in the CMS dataset.
Parent Code
O9A.11
Malignant neoplasm complicating pregnancy

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO94-O9AOther obstetric conditions, not elsewhere classified
CategoryO9AMaternal malignant neoplasms, traumatic injuries and abuse classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
This CodeO9A.111Malignant neoplasm complicating pregnancy, first trimester

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O9A.111.

Maternity diagnoses
The Medicare Code Editor detects inconsistencies in maternity cases by checking a patient's age and any diagnosis on the patient's record. The maternity code edits apply to patients age ange is 9–64 years inclusive (e.g., diabetes in pregnancy, antepartum pulmonary complication).

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR PRG028
Other specified complications in pregnancy
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Tumors and Pregnancy

Tumors during pregnancy are rare, but they can happen. Tumors can be either benign (not cancer) or malignant (cancer). The most common cancers in pregnancy include breast cancer, thyroid cancer, cervical cancer, lymphoma, and melanoma. Cancer itself rarely harms the fetus, and some cancer treatments are safe during pregnancy.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert O9A.111 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
648.91 Oth curr cond-delivered
Approximate The match is approximate rather than exact.
ICD-9-CM
648.93 Oth curr cond-antepartum
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About O9A.111Overview

Is O9A.111 (Malignant neoplasm complicating pregnancy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm complicating pregnancy, first trimester on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does O9A.111 group to?

When malignant neoplasm complicating pregnancy, first trimester is the principal diagnosis on an inpatient stay, it groups to MS-DRG 817, 818, 819, 831, 832, 833, with relative weights from 0.5229 to 1.6880 depending on complications. Higher weights mean higher Medicare reimbursement.

Who can O9A.111 be reported for?

The Medicare Code Editor checks malignant neoplasm complicating pregnancy, first trimester 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 O9A.111?

Under the General Equivalence Mappings, malignant neoplasm complicating pregnancy, first trimester converts to ICD-9-CM 648.91 (oth curr cond-delivered) and 648.93 (oth curr cond-antepartum). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.