ICD-10 Code L13 – Other bullous disorders (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L13 – Other bullous disorders
What it is
L13 is the ICD-10-CM category for other bullous disorders, meaning blistering skin diseases that do not fit a more specific bullous diagnosis. Use it when the record supports a bullous disorder but the exact subtype is not documented.
Clinical signs
Typical findings include tense or fragile blisters, erosions after rupture, and irritation of the skin or mucous membranes. Clinical features vary; refer to documentation for the exact blistering pattern and distribution.
When to use this code
Use L13 when the clinician documents a bullous disorder and no more specific ICD-10-CM code applies. It is appropriate for nonspecific or mixed blistering conditions when the chart does not name a precise diagnosis. Check documentation before coding if the etiology or subtype is unclear.
Do not use for
Do not use L13 if the record identifies a more specific bullous disease, such as a named autoimmune or inherited blistering disorder. Also avoid it when the blistering is clearly due to burns, infection, or another separate cause.
Coding tip
Code the most specific bullous diagnosis documented; if the subtype is missing, L13 may be the correct fallback.