ICD-10-CM 2027
ICD-10 code for seven day fever
From the official ICD-10-CM alphabetic index entry “Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) › seven day (leptospirosis) (autumnal) (Japanese)”. Page updated September 29, 2026.
About coding seven day fever
The ICD-10-CM code for seven day fever is A27.89 (Other forms of leptospirosis). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on A27.89.
Within A27.8, choose A27.89 (Other forms of leptospirosis) only when documentation doesn't support a more specific option: aseptic meningitis in leptospirosis (A27.81).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 023 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulator, relative weight 5.7444), DRG 024 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis without MCC, relative weight 3.9708), DRG 097 (Non-Bacterial Infection of Nervous System Except Viral Meningitis with MCC, relative weight 3.8226), DRG 098 (Non-Bacterial Infection of Nervous System Except Viral Meningitis with CC, relative weight 2.2706) and DRG 099 (Non-Bacterial Infection of Nervous System Except Viral Meningitis without CC/MCC, relative weight 1.5256), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific seven day fever codes (official index)
- dengue A90 — Dengue fever [classical dengue]
Common questions about seven day fever ICD-10 codes
What is the ICD-10 code for seven day fever?
- A27.89 — Other forms of leptospirosis. More specific codes apply when the documentation supports them: A90.
What is the ICD-10 code for dengue seven day fever?
- A90 — Dengue fever [classical dengue].
Is A27.89 billable?
- Yes. A27.89 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A27.89 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A27.89 as a principal diagnosis.
Is A27.89 a CC or MCC?
- A27.89 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.