ICD-10 Code C82.01 – Follicular lymphoma grade I, lymph nodes of head, face, and neck (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C82.01 – Follicular lymphoma grade I, lymph nodes of head, face, and neck
What it is
This code identifies grade I follicular lymphoma, a slow-growing non-Hodgkin lymphoma, when it involves lymph nodes in the head, face, or neck. Use it only when the record specifies both the grade and the nodal site.
Clinical signs
Typical findings include painless enlargement of cervical or other head and neck lymph nodes, sometimes with incidental discovery on exam or imaging. Clinical features vary; refer to documentation.
When to use this code
Use C82.01 when the provider documents grade I follicular lymphoma and states the affected lymph nodes are in the head, face, or neck. This code supports site-specific diagnosis coding and should match the pathology or oncology note. If the site or grade is unclear, check documentation before assigning the code.
Do not use for
Do not use this code for other follicular lymphoma grades or for disease in lymph nodes outside the head, face, and neck. If documentation only says lymphoma or adenopathy without confirmation, check documentation.
Coding tip
Confirm both the histologic grade and anatomic nodal region in the source note before coding C82.01.