Skip to content
Dx

ICD-10-CM 2027 diagnosis code

O99.345Other mental disorders complicating the puerperium

✓ Billable / specificMaternity · age 9–64Female only

O99.345 is a valid, billable ICD-10-CM code for other mental disorders complicating the puerperium. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About O99.345

O99.345 is the ICD-10-CM diagnosis code for other mental disorders complicating the puerperium. It belongs to category O99 (other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium), block O94-O9A (other obstetric conditions, not elsewhere classified) and chapter 15 (pregnancy, childbirth and the puerperium). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within O99.34 (other mental disorders complicating pregnancy, childbirth, and the puerperium), O99.345 is specifically for other mental disorders complicating the puerperium. Related codes cover pregnancy, unspecified trimester (O99.340), pregnancy, first trimester (O99.341), pregnancy, second trimester (O99.342), pregnancy, third trimester (O99.343) and childbirth (O99.344).

Use an additional code to identify specific condition.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 769 (Postpartum and Post Abortion Diagnoses with O.R. Procedures, relative weight 1.6673) and DRG 776 (Postpartum and Post Abortion Diagnoses without O.R. Procedures, relative weight 0.6721), in MDC 14 (Pregnancy, Childbirth and the Puerperium), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

The Medicare Code Editor treats this as a maternity diagnosis, expected only for patients age 9 through 64.

It is on the CMS list of diagnoses consistent only with female patients (the sex-conflict edit itself was retired in FY2025).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 648.42 (mental disorders of mother, delivered, with mention of postpartum complication) and 648.44 (mental disorders of mother, postpartum condition or complication).

Notes that apply from higher levels

Instructions written at a parent level also apply to O99.345.

› From O99.34 Other mental disorders complicating pregnancy, childbirth, and the puerperium
Excludes2
  • postpartum mood disturbance (O90.6)
  • postnatal psychosis (F53.1)
  • puerperal psychosis (F53.1)
› From O99 Other maternal diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
Includes
  • conditions which complicate the pregnant state, are aggravated by the pregnancy or are a main reason for obstetric care
Excludes2
  • when the reason for maternal care is that the condition is known or suspected to have affected the fetus (O35-O36)
Use additional code
  • code to identify specific condition

Broader instructions also apply from Chapter 15: Pregnancy, childbirth and the puerperium.

Alphabetic index entries

1 entries

Terms in the official ICD-10-CM index that lead to O99.345.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 14 · Pregnancy, Childbirth and the Puerperium

MDC 14 · Pregnancy, Childbirth and the Puerperium

ICD-9-CM equivalent

Converter →
  • 648.42Mental disorders of mother, delivered, with mention of postpartum complicationapproximate
  • 648.44Mental disorders of mother, postpartum condition or complicationapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about O99.345

Is O99.345 billable?

Yes. O99.345 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can O99.345 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict O99.345 as a principal diagnosis.

Is O99.345 a CC or MCC?

No. O99.345 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does O99.345 group to?

O99.345 is used in the MS-DRG v44.0 logic for MS-DRG 769 (Postpartum and Post Abortion Diagnoses with O.R. Procedures) and MS-DRG 776 (Postpartum and Post Abortion Diagnoses without O.R. Procedures). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for O99.345?

The CMS General Equivalence Mappings map O99.345 to ICD-9-CM 648.42 and 648.44.