DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

A78 diagnosis code · Billable category · FY2027

A78 Q fever

  • Billable
  • CC
  • POA reported

A78 ICD-10 code: a billable diagnosis code in FY2027; the category has no subdivisions.

Where it sits

  1. Chapter 1 Certain infectious and parasitic diseases (A00-B99)
  2. A75-A79 Rickettsioses (A75-A79)
  3. A78 Q fever
CC / MCC
CC
MS-DRG
867-869
HCC V28
–
POA
Reported
Code Editor
–
Index entries
16

Instructions

At A78

Inclusion terms

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

Notes that also apply

Chapter 1 instructions (Includes 1, Excludes2 5, Use additional code 1): printed on the chapter 1 page.

Index entries

  • Balkan grippe → A78
  • Q fever → A78
  • Quadrilateral fever → A78
  • AustralianQ fever → A78
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Coxiella burnetii → A78 [I39]
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)Q fever → A78 [I39]
  • Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor)Australian Q → A78
  • Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor)Nine-Mile → A78
  • Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor)Q → A78
  • Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor)quadrilateral → A78
  • Grippe, grippalBalkan → A78
  • Infection, infected, infective (opportunistic)Coxiella burnetii → A78
  • Infection, infected, infective (opportunistic)Q fever → A78
  • Q feverwith pneumonia → A78
  • Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)due toQ fever → A78 [I39]
  • Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved)in (due to)Q fever → A78

NCHS Alphabetic Index. Index first, then the Tabular List.

Medicare grouping and edits

CMS files for A78
CC / MCCCC
PDX exclusion list0111 (56 codes)
Appendix BMDC 18 Infectious and Parasitic Diseases, Systemic or Unspecified Sites, MS-DRG 867-869 (Other Infectious and Parasitic Diseases Diagnoses with MCC…)
Code Editor–
POAReported
HCC V28–

CC as a secondary diagnosis, not when the principal diagnosis is on its PDX exclusion list.

CMS: MS-DRG v44 (Appendix B, C), MCE v44, POA list FY2027, 2027 Initial ICD-10-CM Mappings. What the rows mean.

Hierarchy