ICD-10 Code L05.91 – Pilonidal cyst without abscess (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L05.91 – Pilonidal cyst without abscess
What it is
L05.91 identifies a pilonidal cyst in the natal cleft or sacrococcygeal area when there is no abscess. You should use it for a chronic or uncomplicated cystic lesion without documented acute infection.
Clinical signs
Typical findings include a midline pit, swelling, tenderness, or intermittent drainage near the tailbone. If an abscess, cellulitis, or other complication is documented, confirm the code choice.
When to use this code
Use L05.91 when the record clearly documents pilonidal cyst and specifically states no abscess. It also fits follow-up visits for a known cyst without acute drainage or infection. Check documentation if the note only says “pilonidal disease” or “sinus.”
Do not use for
Do not use this code for pilonidal abscess, pilonidal sinus with abscess, or other infected sacrococcygeal disease. If the provider describes a different lesion or uncertain diagnosis, check documentation.
Coding tip
Match the code to the provider’s exact wording and abscess status; if abscess is mentioned, L05.91 is not appropriate.