2026 ICD-10-CM Diagnosis Code O26.879Cervical shortening, unspecified trimester

ICD-10-CM CodesO00-O9AO20-O29O26

ICD-10-CM O26.879
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O26.879 is a billable ICD-10-CM diagnosis code for cervical shortening, unspecified 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). Coders also document this condition as short cervical length in pregnancy. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Early or threatened labor.

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
O26.879
Billable Status
Yes — Valid for Submission
Code Describes
Cervical shortening, unspecified trimester
Short Description
Cervical shortening, unspecified trimester
Same as the full description in the CMS dataset.
Parent Code
Cervical shortening

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO20-O29Other maternal disorders predominantly related to pregnancy
CategoryO26Maternal care for other conditions predominantly related to pregnancy
This CodeO26.879Cervical shortening, unspecified trimester

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O26.879.

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).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Short cervical length in pregnancy

Clinical ClassificationClinical

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

CCSR PRG011
Early or threatened labor
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Cervix Disorders

A cervix disorder is a problem with your cervix. The cervix is part of the female reproductive system. It is the lower, narrow end of the uterus (womb), which opens into the vagina (birth canal). The cervix has a small opening that expands during childbirth. It also allows menstrual blood to leave your body.

The full article covers:

  • What is a cervix disorder?
  • Who is more likely to develop cervix disorders?
  • What are the symptoms of cervix disorders?
  • How are cervix disorders diagnosed?
  • What are the treatments for cervix disorders?
  • Can cervix disorders be prevented?

Read the full article at MedlinePlus

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

Convert O26.879 to ICD-9-CMHistory

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

ICD-9-CM
649.70 Cervical shortening-unsp
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 O26.879Overview

Is O26.879 (Cervical shortening) a billable code?

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

What MS-DRG does O26.879 group to?

When cervical shortening, unspecified 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 O26.879 be reported for?

The Medicare Code Editor checks cervical shortening, unspecified 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 O26.879?

Under the General Equivalence Mappings, cervical shortening, unspecified trimester converts to ICD-9-CM 649.70 (cervical shortening-unsp). 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.