ICD-10-CM 2027
ICD-10 code for leptospirosis
From the official ICD-10-CM alphabetic index entry “Leptospirosis”. Page updated September 29, 2026.
About coding leptospirosis
The ICD-10-CM code for leptospirosis is A27.9 (Leptospirosis, unspecified). The official index lists 5 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on A27.9.
Within A27, choose A27.9 (unspecified) only when documentation doesn't support a more specific option: icterohemorrhagica (A27.0) and other forms of leptospirosis (A27.8).
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 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC, relative weight 2.1859), DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC, relative weight 1.0235) and DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), 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 leptospirosis codes (official index)
- canicola A27.89 — Other forms of leptospirosis
- due to Leptospira interrogans serovar icterohaemorrhagiae A27.0 — Leptospirosis icterohemorrhagica
- icterohemorrhagica A27.0 — Leptospirosis icterohemorrhagica
- pomona A27.89 — Other forms of leptospirosis
- Weil's disease A27.0 — Leptospirosis icterohemorrhagica
Common questions about leptospirosis ICD-10 codes
What is the ICD-10 code for leptospirosis?
- A27.9 — Leptospirosis, unspecified. More specific codes apply when the documentation supports them: A27.89, A27.0, A27.0, A27.89 and others below.
What is the ICD-10 code for canicola leptospirosis?
- A27.89 — Other forms of leptospirosis.
What is the ICD-10 code for icterohemorrhagica leptospirosis?
- A27.0 — Leptospirosis icterohemorrhagica.
What is the ICD-10 code for pomona leptospirosis?
- A27.89 — Other forms of leptospirosis.
What is the ICD-10 code for weil's disease leptospirosis?
- A27.0 — Leptospirosis icterohemorrhagica.
Is A27.9 billable?
- Yes. A27.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A27.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A27.9 as a principal diagnosis.
Is A27.9 a CC or MCC?
- A27.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.