2027 ICD-10-CM Diagnosis Code O9A.119Malignant neoplasm complicating pregnancy, unspecified trimester
ICD-10-CM Codes›O00-O9A›O94-O9A›O9A
- Billable — Valid for Submission
- Chronic Condition
O9A.119 is a billable ICD-10-CM diagnosis code for malignant neoplasm complicating pregnancy, unspecified trimester. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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). Coders also document this condition as malignancy diagnosed during pregnancy. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified complications in pregnancy.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O9A.119.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Malignancy diagnosed during pregnancy
- Malignant neoplastic disease in pregnancy
- Materno-fetal metastatic malignant melanoma
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to O9A.119: its own notes plus those printed at O9A.1 and Chapter 15. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- supervision of normal pregnancy (Z34.-)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify neoplasm
- code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.
Notes
General instructions on how these codes are used.
- CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
- Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
- Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
- 1st trimester- less than 14 weeks 0 days
- 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
- 3rd trimester- 28 weeks 0 days until delivery
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name O9A.119, its category, or a range that includes it.
Excludes2 2
These codes carry an Excludes2 note naming O9A.119: its condition is not part of those codes, and both may be reported when the patient has both.
- O34.1 Maternal care for benign tumor of corpus uterimaternal care for malignant neoplasm of uterus (O9A.1-) names O9A.1-, which includes this code
- O99.8 Other specified diseases and conditions complicating pregnancy, childbirth and the puerperiummalignant neoplasm complicating pregnancy, childbirth and the puerperium (O9A.1-) names O9A.1-, which includes this code
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.119 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About O9A.119Overview
What is the ICD-10 code for malignant neoplasm complicating pregnancy, unspecified trimester?
The ICD-10-CM code for malignant neoplasm complicating pregnancy, unspecified trimester is O9A.119 (sometimes written as O9A119). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is O9A.119 (Malignant neoplasm complicating pregnancy) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm complicating pregnancy, unspecified trimester on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does O9A.119 group to?
When malignant neoplasm complicating pregnancy, unspecified trimester is the principal diagnosis on an inpatient stay, it groups to MS-DRG 833, 832, 831, 819, 818, 817, with relative weights from 0.5000 to 1.7586 depending on complications. Higher weights mean higher Medicare reimbursement.
Who can O9A.119 be reported for?
The Medicare Code Editor checks malignant neoplasm complicating pregnancy, unspecified trimester against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
Does O9A.119 need an additional code?
When the condition applies, yes. The Use Additional Code note at O9A.1, which applies to O9A.119, reads: code to identify neoplasm. The additional code is reported after O9A.119.
