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ICD-10-CM 2027 diagnosis code

O86.4Pyrexia of unknown origin following delivery

✓ Billable / specificCC — complication/comorbidityMaternity · age 9–64Female only

O86.4 is a valid, billable ICD-10-CM code for pyrexia of unknown origin following delivery. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Puerperal infection, ICD-10 code for Infection puerperal.

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 O86.4

O86.4 is the ICD-10-CM diagnosis code for pyrexia of unknown origin following delivery. It belongs to category O86 (other puerperal infections), block O85-O92 (complications predominantly related to the puerperium) 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 O86 (other puerperal infections), O86.4 is specifically for pyrexia of unknown origin following delivery. Related codes cover infection of obstetric surgical wound (O86.0), other infection of genital tract following delivery (O86.1), urinary tract infection following delivery (O86.2) and other specified puerperal infections (O86.8).

The conditions in its Excludes2 note aren't part of O86.4, but may be coded alongside it if the patient has both: pyrexia during labor (O75.2).

Use an additional code (B95-B97), to identify infectious agent.

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

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 672.02 (pyrexia of unknown origin during the puerperium, delivered, with mention of postpartum complication) and 672.04 (pyrexia of unknown origin during the puerperium, postpartum condition or complication).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Puerperal infection NOS following delivery
  • Puerperal pyrexia NOS following delivery
Excludes2Not included here — may be reported together if both conditions exist
  • pyrexia during labor (O75.2)

Notes that apply from higher levels

Instructions written at a parent level also apply to O86.4.

› From O86 Other puerperal infections
Excludes2
  • infection during labor (O75.3)
  • obstetrical tetanus (A34)
Use additional code
  • code (B95-B97), to identify infectious agent

Broader instructions also apply from O85-O92 Complications predominantly related to the puerperium and Chapter 15: Pregnancy, childbirth and the puerperium.

Alphabetic index entries

8 entries

Terms in the official ICD-10-CM index that lead to O86.4.

Codes whose notes reference O86.4

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 →
  • 672.02Pyrexia of unknown origin during the puerperium, delivered, with mention of postpartum complicationapproximate
  • 672.04Pyrexia of unknown origin during the puerperium, 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 O86.4

Is O86.4 billable?

Yes. O86.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can O86.4 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict O86.4 as a principal diagnosis.

Is O86.4 a CC or MCC?

O86.4 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does O86.4 group to?

O86.4 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 O86.4?

The CMS General Equivalence Mappings map O86.4 to ICD-9-CM 672.02 and 672.04.