2027 ICD-10-CM Diagnosis Code O99.340Other mental disorders complicating pregnancy, unspecified trimester
ICD-10-CM Codes›O00-O9A›O94-O9A›O99
- Billable — Valid for Submission
- Not Chronic
O99.340 is a billable ICD-10-CM diagnosis code for other mental disorders complicating pregnancy, unspecified 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. 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 Miscellaneous mental and behavioral disorders/conditions and Other specified complications in pregnancy.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O99.340.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adjustment disorder during pregnancy
- Antenatal depression
- Anxiety disorder in pregnancy
- Anxiety in pregnancy
- Depressive disorder in mother complicating pregnancy
- Grieving process during pregnancy
- Major depressive disorder in mother complicating pregnancy
- Mental disorder in mother complicating pregnancy
- Mental disorders during pregnancy, childbirth and the puerperium
- Mood disorder during pregnancy
- Psychological disorder during pregnancy
- Psychotic disorder in mother complicating pregnancy
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to O99.340: its own notes plus those printed at O99.34, O99, 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.
- conditions which complicate the pregnant state, are aggravated by the pregnancy or are a main reason for obstetric care
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.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify 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.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 O99.340 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About O99.340Overview
What is the ICD-10 code for other mental disorders complicating pregnancy, unspecified trimester?
The ICD-10-CM code for other mental disorders complicating pregnancy, unspecified trimester is O99.340 (sometimes written as O99340). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is O99.340 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other mental disorders complicating pregnancy, unspecified trimester on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does O99.340 group to?
When other mental disorders complicating pregnancy, unspecified 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.
Who can O99.340 be reported for?
The Medicare Code Editor checks other mental disorders complicating pregnancy, unspecified trimester against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
Does O99.340 need an additional code?
When the condition applies, yes. The Use Additional Code note at O99, which applies to O99.340, reads: code to identify specific condition. The additional code is reported after O99.340.
