O86.4 Pyrexia of unknown origin following delivery

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

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

Excludes2 (not included here)

• pyrexia during labor (O75.2)

Applies from O86 Other puerperal infections

Excludes2 (not included here)

• infection during labor (O75.3)
• obstetrical tetanus (A34)

Use additional code

• code (B95-B97), to identify infectious agent

MS-DRG index

Defines the logic of DRG(s) 769 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 672.02 Pyrexia of unknown origin during the puerperium, delivered, with mention of postpartum complication (approximate)
• 672.04 Pyrexia of unknown origin during the puerperium, postpartum condition or complication (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Maternity diagnoses (age 9 through 64): Age conflict edit. These diagnoses are clinically expected only in patients age 9 through 64.

Code annotations containing back-references to O86.4

Back-references to O86.4

• Type 1 Excludes: O85 Puerperal sepsis ("fever of unknown origin following delivery (O86.4)")
• Type 2 Excludes: O99.8 Other specified diseases and conditions complicating pregnancy, childbirth and the puerperium ("infection of genitourinary tract following delivery (O86.1-O86.4)")
• Type 1 Excludes: R50 Fever of other and unknown origin ("puerperal pyrexia NOS (O86.4)")

Back-references to O86

• Type 1 Excludes: N71 Inflammatory disease of uterus, except cervix ("infection of uterus following delivery (O85, O86.-)")
• Type 2 Excludes: O75 Other complications of labor and delivery, not elsewhere classified ("puerperal (postpartum) infection (O86.-)")
• Type 2 Excludes: O98 Maternal infectious and parasitic diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium ("puerperal infection (O86.-)")

Diagnosis Index entries for O86.4

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

Nearby codes

• O86.2 Urinary tract infection following delivery
• O86.20 Urinary tract infection following delivery, unspecified
• O86.21 Infection of kidney following delivery
• O86.22 Infection of bladder following delivery
• O86.29 Other urinary tract infection following delivery
• O86.4 Pyrexia of unknown origin following delivery (this code)
• O86.8 Other specified puerperal infections
• O86.81 Puerperal septic thrombophlebitis
• O86.89 Other specified puerperal infections