A31.1 — Cutaneous mycobacterial infection
Is A31.1 billable?
Yes — A31.1 is billable for FY2027. A31.1 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. A31.1 may be submitted for encounters from October 1, 2026 through September 30, 2027.
A31.1 at a glance
| Code | A31.1 |
|---|---|
| Description | Cutaneous mycobacterial infection |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does A31.1 group to?
A31.1 sits in MDC 09 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 606Minor Skin Disorders with MCCmedical
- 607Minor Skin Disorders without MCCmedical
As a secondary diagnosis, A31.1 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is A31.1 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to A31.1. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Buruli ulcer
- Disease, diseased › swimming-pool granuloma
- Granuloma › swimming pool
- Infection, infected, infective › swimming pool bacillus (opportunistic)
- Mycobacterium, mycobacterial › balnei (infection)
- Mycobacterium, mycobacterial › cutaneous (infection)
- Mycobacterium, mycobacterial › luciflavum (infection)
- Mycobacterium, mycobacterial › marinum (infection)
- Mycobacterium, mycobacterial › ulcerans (infection)
- Ulcer, ulcerated, ulcerating, ulceration, ulcerative › Buruli
- Ulcer, ulcerated, ulcerating, ulceration, ulcerative › mycobacterial
- Infection, infected, infective › Bacillus › swimming pool (opportunistic)
Inclusion terms
Alternative wording in documentation that is classified to A31.1.
- Buruli ulcer
- Infection due to Mycobacterium marinum
- Infection due to Mycobacterium ulcerans
Use additional code — inherited from Chapter 1
Report an additional code alongside A31.1 to fully describe the condition. A31.1 is sequenced first.
- code to identify resistance to antimicrobial drugs (Z16.-)
Excludes2 — not included here — inherited from Chapter 1
The conditions below are not part of A31.1, but a patient may have both at the same time. When documentation supports it, A31.1 and the excluded code may both be reported.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Excludes2 — not included here — inherited from A31
The conditions below are not part of A31.1, but a patient may have both at the same time. When documentation supports it, A31.1 and the excluded code may both be reported.
How long has A31.1 existed?
A31.1 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.