ICD-10 Code L65.1 – Anagen effluvium (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L65.1 – Anagen effluvium
What it is
Anagen effluvium is rapid hair loss that occurs during the active growth phase of the hair cycle. It is usually linked to a direct injury to growing hair follicles, often from chemotherapy or other toxic exposures.
Clinical signs
You may see sudden, diffuse hair shedding or breakage affecting scalp hair and sometimes eyebrows or body hair. Clinical features vary; refer to documentation.
When to use this code
Use this code when the record documents hair loss specifically identified as anagen effluvium. It fits cases where the clinician links the loss to a known trigger, such as cytotoxic therapy or another follicular insult. Check documentation if the type of alopecia is not clearly stated.
Do not use for
Do not use this code for androgenic alopecia, alopecia areata, or nonspecific hair loss without documentation of anagen effluvium. If the cause is unclear, check documentation.
Coding tip
Code L65.1 only when the provider explicitly identifies anagen effluvium or documents a matching cause and pattern.