ICD-10-CM 2027
ICD-10 code for erythema tuberculosis
From the official ICD-10-CM alphabetic index entry “Tuberculosis, tubercular, tuberculous (calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative) › erythema (induratum) (nodosum) (primary)”. Page updated September 29, 2026.
About coding erythema tuberculosis
The ICD-10-CM code for erythema tuberculosis is A18.4 (Tuberculosis of skin and subcutaneous tissue).
Within A18 (tuberculosis of other organs), A18.4 is specifically for tuberculosis of skin and subcutaneous tissue. Related codes cover tuberculosis of bones and joints (A18.0), tuberculosis of genitourinary system (A18.1), tuberculous peripheral lymphadenopathy (A18.2), tuberculosis of intestines, peritoneum and mesenteric glands (A18.3), tuberculosis of eye (A18.5), tuberculosis of (inner) (middle) ear (A18.6), tuberculosis of adrenal glands (A18.7) and tuberculosis of other specified organs (A18.8).
The conditions in its Excludes2 note aren't part of A18.4, but may be coded alongside it if the patient has both: lupus erythematosus (L93.-) and systemic lupus erythematosus (M32.-).
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.
Common questions about erythema tuberculosis ICD-10 codes
What is the ICD-10 code for erythema tuberculosis?
- A18.4 — Tuberculosis of skin and subcutaneous tissue.
Is A18.4 billable?
- Yes. A18.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A18.4 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A18.4 as a principal diagnosis.
Is A18.4 a CC or MCC?
- A18.4 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.