Infection due to other mycobacteria (A31) ICD-10-CM
The A31 code range covers infection due to other mycobacteria with 6 ICD-10-CM diagnosis codes. 5 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Codes in the A31 Range 6 codes · 5 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the A31 range.
Buruli Ulcer
A lesion in the skin and subcutaneous tissues due to infections by MYCOBACTERIUM ULCERANS. It was first reported in Uganda, Africa.
Mycobacterium ulcerans
A slow-growing mycobacterium that infects the skin and subcutaneous tissues, giving rise to indolent BURULI ULCER.
About the A31 Code Range
ICD-10 code A31 and its subcodes identify infections caused by mycobacteria other than tuberculosis and leprosy, known as atypical or non-tuberculous mycobacterial infections. These codes are used to classify various infections affecting lungs, skin, disseminated organs, and other tissues.
The ICD-10 code A31.0 refers specifically to pulmonary mycobacterial infections, including diseases like Mycobacterium kansasii infection, pulmonary Mycobacterium avium complex infection, and Lady Windermere syndrome. This code helps document lung infections from species such as Mycobacterium malmoense, xenopi, and intracellulare. Code A31.1 covers cutaneous mycobacterial infections, including Buruli ulcer and fish tank granuloma, with involvement from species like Mycobacterium marinum and scrofulaceum. The A31.2 code relates to disseminated infections by the Mycobacterium avium-intracellulare complex (DMAC), often seen in compromised immune systems. A31.8 serves for other diverse mycobacterial infections such as mycobacterial arthritis, spondyloarthritis, and keratitis caused by various atypical mycobacteria. The unspecified A31.9 code is used when the infection is identified as mycobacterial but lacks clear localization or specific species diagnosis. Understanding these distinctions supports accurate coding for conditions caused by non-tuberculous mycobacteria, assisting clinicians and coders in precise classification and management.
Questions About This Page
How many billable codes are in the A31 range?
Of the 6 codes in this range, 5 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 A31 range classify?
The range classifies infection due to other mycobacteria. 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.
