O86.4 Pyrexia of unknown origin following delivery

The ICD-10-CM code for Pyrexia of unknown origin following delivery is O86.4 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

15: Pregnancy, childbirth and the puerperium (O00-O9A)

Section

O85-O92: Complications predominantly related to the puerperium (O85-O92)

Category O86

22 codes (17 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to O86.4:

• Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) › puerperal
• Puerperal, puerperium (complicated by, complications) › infection
• Pyrexia (of unknown origin) › puerperal
• Puerperal, puerperium (complicated by, complications) › fever (of unknown origin)
• Puerperal, puerperium (complicated by, complications) › pyrexia (of unknown origin)
• Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) › following delivery
• Infection, infected, infective (opportunistic) › puerperal
• Infection, infected, infective (opportunistic) › puerperal › minor

Inclusion Terms

• Puerperal infection NOS following delivery
• Puerperal pyrexia NOS following delivery

U.S. Hospital Utilization

• An estimated 8,335 U.S. inpatient stays in 2023 included O86.4 among the documented diagnoses.
• 435 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)