ICD-10 Code L05.01 – Pilonidal cyst with abscess (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L05.01 – Pilonidal cyst with abscess
What it is
This code identifies a pilonidal cyst in the natal cleft that has become infected and formed an abscess. It usually refers to a painful, localized collection of pus near the tailbone.
Clinical signs
Typical findings include swelling, tenderness, redness, and drainage in the sacrococcygeal area. Clinical features vary; refer to documentation.
When to use this code
Use L05.01 when the record clearly documents a pilonidal cyst with abscess, including an infected or draining lesion in the natal cleft. Code it when the provider describes abscess formation rather than an uncomplicated pilonidal cyst. Check documentation if the note only says “pilonidal disease” or “cyst” without abscess.
Do not use for
Do not use this code for an uncomplicated pilonidal cyst without abscess. If the documentation is unclear about infection or abscess, do not assume L05.01.
Coding tip
Confirm that the provider explicitly documents abscess or infection before assigning L05.01.