2026 ICD-10-CM Diagnosis Code O99.211Obesity complicating pregnancy, first trimester

ICD-10-CM Codes›O00-O9A›O94-O9A›O99

ICD-10-CM O99.211
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O99.211 is a billable ICD-10-CM diagnosis code for obesity 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 Obesity and Other specified complications in pregnancy.

Code Identity

ICD-10-CM Code
O99.211
Billable Status
Yes — Valid for Submission
Code Describes
Obesity complicating pregnancy, first trimester
Short Description
Obesity complicating pregnancy, first trimester
Same as the full description in the CMS dataset.
Parent Code
O99.21
Obesity complicating pregnancy, childbirth, and the puerperium

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO94-O9AOther obstetric conditions, not elsewhere classified
CategoryO99Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
This CodeO99.211Obesity complicating pregnancy, first trimester

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O99.211.

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 END009
Obesity
Default principal diagnosis: inpatient No · outpatient No
CCSR PRG028
Other specified complications in pregnancy
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Health Problems in Pregnancy

A health problem in pregnancy is any disease or condition that could affect your health or the health of your fetus. Some health problems may make it more likely that you will have a high-risk pregnancy. A high-risk pregnancy is one in which you, your fetus, or both are at higher risk for health problems than in a typical pregnancy.

The full article covers:

  • What are health problems in pregnancy?
  • What raises my risk for health problems during pregnancy?
  • Can chronic health conditions cause problems in pregnancy?
  • Can health problems in pregnancy be prevented?

Read the full article at MedlinePlus

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

Convert O99.211 to ICD-9-CMHistory

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

ICD-9-CM
649.11 Obesity-delivered
Approximate The match is approximate rather than exact.
ICD-9-CM
649.13 Obesity-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 O99.211Overview

Is O99.211 a billable code?

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

What MS-DRG does O99.211 group to?

When obesity 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 O99.211 be reported for?

The Medicare Code Editor checks obesity 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 O99.211?

Under the General Equivalence Mappings, obesity complicating pregnancy, first trimester converts to ICD-9-CM 649.11 (obesity-delivered) and 649.13 (obesity-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.