ICD-10 Code K60.321 – Anal fistula, complex, initial (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K60.321 – Anal fistula, complex, initial
What it is
This code identifies a complex anal fistula at the initial encounter. A complex fistula is an abnormal tract near the anus that is more extensive or difficult to manage than a simple fistula.
Clinical signs
Typical findings include persistent perianal drainage, pain, swelling, or recurrent abscesses. Clinical features vary; refer to documentation for tract complexity, associated abscess, or involvement of deeper structures.
When to use this code
Use K60.321 when documentation clearly states a complex anal fistula and the encounter is initial. This may include evaluation, workup, or first treatment planning for the condition. Verify that the provider has not described a different anorectal disorder.
Do not use for
Do not use this code for a simple anal fistula, a healed condition, or follow-up care after the initial encounter. Check documentation if the record only mentions abscess, fissure, or nonspecific perianal symptoms.
Coding tip
Confirm both complexity and encounter type in the note before assigning K60.321.