2026 ICD-10-CM Diagnosis Code O29.012Aspiration pneumonitis due to anesthesia during pregnancy, second trimester

ICD-10-CM Codes›O00-O9A›O20-O29›O29

ICD-10-CM O29.012
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O29.012 is a billable ICD-10-CM diagnosis code for aspiration pneumonitis due to anesthesia during pregnancy, second 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 Anesthesia complications during pregnancy and Aspiration pneumonitis.

This medical diagnosis code is frequently used in OB/GYN medical specialties to designate conditions such maternal disorders related to pregnancy.

Code Identity

ICD-10-CM Code
O29.012
Billable Status
Yes — Valid for Submission
Code Describes
Aspiration pneumonitis due to anesthesia during pregnancy, second trimester
Short Description
Aspirat pneumonitis due to anesth during preg, second tri
Parent Code
O29.01
Aspiration pneumonitis due to anesthesia during pregnancy

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO20-O29Other maternal disorders predominantly related to pregnancy
CategoryO29Complications of anesthesia during pregnancy
This CodeO29.012Aspiration pneumonitis due to anesthesia during pregnancy, second trimester

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O29.012.

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 PRG025
Anesthesia complications during pregnancy
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR RSP010
Aspiration pneumonitis
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Anesthesia

Anesthesia is the use of medicines, called anesthetics, to prevent pain during surgery and other medical procedures. Medicine may be given by injection, inhalation, topical lotion, spray, eye drops, or a skin patch.

The full article covers:

  • What is anesthesia?
  • What is anesthesia used for?
  • What are the types of anesthesia?
  • What are the risks of anesthesia?

Read the full article at MedlinePlus

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

Convert O29.012 to ICD-9-CMHistory

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

ICD-9-CM
646.81 Preg compl NEC-delivered
Approximate The match is approximate rather than exact.
ICD-9-CM
646.83 Preg compl NEC-antepart
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 O29.012Overview

Is O29.012 (Aspiration pneumonitis due to anesthesia during pregnancy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report aspiration pneumonitis due to anesthesia during pregnancy, second trimester on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does O29.012 group to?

When aspiration pneumonitis due to anesthesia during pregnancy, second 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 O29.012 be reported for?

The Medicare Code Editor checks aspiration pneumonitis due to anesthesia during pregnancy, second 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 O29.012?

Under the General Equivalence Mappings, aspiration pneumonitis due to anesthesia during pregnancy, second trimester converts to ICD-9-CM 646.81 (preg compl NEC-delivered) and 646.83 (preg compl NEC-antepart). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.