2027 ICD-10-CM Diagnosis Code O34.31Maternal care for cervical incompetence, first trimester
ICD-10-CM Codes›O00-O9A›O30-O48›O34
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Not Chronic
O34.31 is a billable ICD-10-CM diagnosis code for maternal care for cervical incompetence, first 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. 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 6 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 Early or threatened labor.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O34.31.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to O34.31: its own notes plus those printed at O34 and Chapter 15. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- the listed conditions as a reason for hospitalization or other obstetric care of the mother, or for cesarean delivery before onset of labor
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.
Code First
The underlying condition named in the note is sequenced before this code.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code for specific condition
- 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 O34.31, its category, or a range that includes it.
Applicable To 1
These notes mention O34.31.
Excludes1 1
These codes carry an Excludes1 note naming O34.31: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 1
These codes carry an Excludes2 note naming O34.31: its condition is not part of those codes, and both may be reported when the patient has both.
Use Additional Code 1
These codes say to use an additional code from the note, and O34.31 is one of the codes named.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 O34.31 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About O34.31Overview
What is the ICD-10 code for maternal care for cervical incompetence, first trimester?
The ICD-10-CM code for maternal care for cervical incompetence, first trimester is O34.31 (sometimes written as O3431). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is O34.31 (Maternal care for cervical incompetence) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report maternal care for cervical incompetence, first trimester on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does O34.31 group to?
When maternal care for cervical incompetence, first 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.
Is O34.31 a CC or MCC?
CMS lists O34.31 as an MCC (major complication or comorbidity) for FY 2027. 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 6 closely related codes in its exclusion list.
Who can O34.31 be reported for?
The Medicare Code Editor checks maternal care for cervical incompetence, first trimester against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
