Leptospirosis (A27) ICD-10-CM
The A27 code range covers leptospirosis with 6 ICD-10-CM diagnosis codes. 4 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Codes in the A27 Range 6 codes · 4 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the A27 range.
Leptospira
A genus of aerobic, helical spirochetes, some species of which are pathogenic, others free-living or saprophytic.
Leptospirosis
Infections with bacteria of the genus LEPTOSPIRA.
Orientia tsutsugamushi
A gram-negative, rod-shaped to coccoid bacterium. It is the etiologic agent of SCRUB TYPHUS in humans and is transmitted by mites from rodent reservoirs.
Scrub Typhus
An acute infectious disease caused by ORIENTIA TSUTSUGAMUSHI. It is limited to eastern and southeastern Asia, India, northern Australia, and the adjacent islands. Characteristics include the formation of a primary cutaneous lesion at the site of the bite of an infected mite, fever lasting about two weeks, and a maculopapular rash.
Weil Disease
A severe form of LEPTOSPIROSIS, usually caused by LEPTOSPIRA INTERROGANS SEROVAR ICTEROHAEMORRHAGIAE and occasionally other serovars. It is transmitted to humans by the rat and is characterized by hemorrhagic and renal symptoms with accompanying JAUNDICE.
About the A27 Code Range
ICD-10 code section A27 specifically classifies leptospirosis, a bacterial infection caused by Leptospira species. This section captures various clinical forms including Weil's disease and leptospiral meningitis, distinguishing them by severity and complications.
This coding group includes A27.0 for icterohemorrhagic leptospirosis, commonly known as Weil's disease, which is a severe form featuring jaundice and bleeding. Code A27.81 covers aseptic meningitis caused by leptospirosis, identified by inflammation of the membranes surrounding the brain and spinal cord, also termed leptospiral meningitis or meningitis caused by spirochetes. Codes A27.8 and A27.89 track other less common forms, including infections linked to various Leptospira species and conditions such as Canicola fever and leptospirosis-related uveitis. The unspecified code A27.9 is used when the exact form of leptospirosis is not documented but includes presentations such as leptospiral rash, pulmonary hemorrhage, and encephalitis. Using the appropriate code helps healthcare professionals accurately report and manage leptospirosis cases.
Questions About This Page
How many billable codes are in the A27 range?
Of the 6 codes in this range, 4 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the A27 range classify?
The range classifies leptospirosis. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
