2026 ICD-10-CM Diagnosis Code O99.345Other mental disorders complicating the puerperium

ICD-10-CM Codes›O00-O9A›O94-O9A›O99

ICD-10-CM O99.345
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O99.345 is a billable ICD-10-CM diagnosis code for other mental disorders complicating the puerperium. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). 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 Complications specified during the puerperium and Miscellaneous mental and behavioral disorders/conditions.

Code Identity

ICD-10-CM Code
O99.345
Billable Status
Yes — Valid for Submission
Code Describes
Other mental disorders complicating the puerperium
Short Description
Other mental disorders complicating the puerperium
Same as the full description in the CMS dataset.
Parent Code
O99.34
Other mental disorders 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 CodeO99.345Other mental disorders complicating the puerperium

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O99.345.

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).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bipolar affective disorder, most recent episode mixed
  • Bipolar disorder, most recent episode manic
  • Bipolar I disorder, most recent episode depressed with postpartum onset
  • Bipolar I disorder, most recent episode depression
  • Bipolar I disorder, most recent episode manic
  • Bipolar I disorder, most recent episode manic with postpartum onset
  • Bipolar I disorder, most recent episode mixed with postpartum onset
  • Mental disorder during puerperium
  • Postpartum adjustment disorder
  • Postpartum anxiety
  • Postpartum depression
  • Recurrent major depressive disorder with postpartum onset

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Puerperal, puerperium(complicated by, complications)
      • mental disorder NEC

Clinical ClassificationClinical

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

CCSR PRG027
Complications specified during the puerperium
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR MBD013
Miscellaneous mental and behavioral disorders/conditions
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Mental Disorders

Mental disorders (or mental illnesses) are conditions that affect your thinking, feeling, mood, and behavior. They may happen over a short period of time or come and go. Some can be chronic (long-lasting). They can affect your ability to relate to others and function each day..

The full article covers:

  • What are mental disorders?
  • What are some types of mental disorders?
  • What causes mental disorders?
  • Who is at risk for mental disorders?
  • How are mental disorders diagnosed?
  • What are the treatments for mental disorders?

Read the full article at MedlinePlus

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

Convert O99.345 to ICD-9-CMHistory

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

ICD-9-CM
648.42 Mental dis-deliv w p/p
Approximate The match is approximate rather than exact.
ICD-9-CM
648.44 Mental disorder-postpart
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 O99.345Overview

Is O99.345 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other mental disorders complicating the puerperium on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Who can O99.345 be reported for?

The Medicare Code Editor checks other mental disorders complicating the puerperium 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 O99.345?

Under the General Equivalence Mappings, other mental disorders complicating the puerperium converts to ICD-9-CM 648.42 (mental dis-deliv w p/p) and 648.44 (mental disorder-postpart). 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.