2026 ICD-10-CM Diagnosis Code O15.03Eclampsia complicating pregnancy, third trimester

ICD-10-CM Codes›O00-O9A›O10-O16›O15

ICD-10-CM O15.03
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O15.03 is a billable ICD-10-CM diagnosis code for eclampsia complicating pregnancy, third 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. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 298 closely related codes. 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 Hypertension and hypertensive-related conditions complicating pregnancy; childbirth; and the puerperium.

Code Identity

ICD-10-CM Code
O15.03
Billable Status
Yes — Valid for Submission
Code Describes
Eclampsia complicating pregnancy, third trimester
Short Description
Eclampsia complicating pregnancy, third trimester
Same as the full description in the CMS dataset.
Parent Code
O15.0
Eclampsia complicating pregnancy

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO10-O16Edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium
CategoryO15Eclampsia
This CodeO15.03Eclampsia complicating pregnancy, third trimester

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O15.03.

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 PRG020
Hypertension and hypertensive-related conditions complicating pregnancy; childbirth; and the puerperium
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

High Blood Pressure in Pregnancy

Blood pressure is the force of your blood pushing against the walls of your arteries. Your arteries are blood vessels that carry blood from your heart to other parts of your body. High blood pressure, or hypertension, is blood pressure that is higher than normal.

The full article covers:

  • What is high blood pressure in pregnancy?
  • What are the types of high blood pressure in pregnancy?
  • Who is more likely to develop high blood pressure in pregnancy?
  • What are the symptoms of high blood pressure in pregnancy?
  • What problems can high blood pressure in pregnancy cause?
  • How is high blood pressure in pregnancy diagnosed?
  • What are the treatments for high blood pressure in pregnancy?

Read the full article at MedlinePlus

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

Convert O15.03 to ICD-9-CMHistory

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

ICD-9-CM
642.61 Eclampsia-delivered
Approximate The match is approximate rather than exact.
ICD-9-CM
642.63 Eclampsia-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 O15.03Overview

What is the ICD-10 code for eclampsia complicating pregnancy, third trimester?

The ICD-10-CM code for eclampsia complicating pregnancy, third trimester is O15.03 (sometimes written as O1503). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is O15.03 (Eclampsia complicating pregnancy) a billable code?

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

What MS-DRG does O15.03 group to?

When eclampsia complicating pregnancy, third 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.

Is O15.03 a CC or MCC?

CMS lists O15.03 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 298 closely related codes in its exclusion list.

Who can O15.03 be reported for?

The Medicare Code Editor checks eclampsia complicating pregnancy, third trimester against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.