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O86.4

O86.4Pyrexia of unknown origin following delivery

Billable / specific codeICD-10-CM

O86.4 is a billable, specific ICD-10-CM code for pyrexia of unknown origin following delivery. It is valid for submission on a claim.

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • pyrexia during labor (O75.2)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

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

Other codes that can never be billed with O86.4

These codes carry an Excludes1 note pointing at O86.4. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading O86.4 alone.

  • O85Puerperal sepsis
  • R50Fever of other and unknown origin

Risk adjustment

O86.4 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

How O86.4 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to O86.4.

  • Feverfollowing delivery
  • Feverpuerperal
  • Infection, infected, infectivepuerperal
  • Puerperal, puerperiumfever(of unknown origin)
  • Puerperal, puerperiuminfection
  • Puerperal, puerperiumpyrexia(of unknown origin)
  • Pyrexiapuerperal
  • Infection, infected, infectivepuerperalminor

Related codes at this level

Codes that share O86. If O86.4 is not quite right, the correct code is usually one of these.

Questions about O86.4

Is O86.4 a billable ICD-10-CM code?
Yes. O86.4 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does O86.4 sit in the tabular list?
Pregnancy, childbirth and the puerperium (O00-O9A), in the block Complications predominantly related to the puerperium (O85-O92).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.