ICD10BillableValid for clinical use

ICD-10 Code A78: Q fever

A78 is a billable ICD-10 diagnosis code used to classify Q fever in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).

When is it used?

  • May be used when a clinician documents q fever in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
1Certain infectious and parasitic diseases (A00-B99)
block
A75-A79Rickettsioses
currentA75-A79

Official coding notes

Inclusion terms
  • Infection due to Coxiella burnetii
  • Nine Mile fever
  • Quadrilateral fever

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

Infectious Disease SpecialistGeneral Physician

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
A78

Common synonyms

Q fever

Frequently asked questions

Code details

CodeA78
SystemICD10
Display nameQ fever
ChapterCertain infectious and parasitic diseases (A00-B99)
BlockRickettsioses

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
AustralianBalkan grippeEndocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)Grippe, grippalInfection, infected, infective(opportunistic)Infection, infected, infective(opportunistic)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code A78 for Q fever | HealthAssure