ICD-10 Code C82.40 – Follicular lymphoma grade IIIb, unspecified site (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C82.40 – Follicular lymphoma grade IIIb, unspecified site
What it is
This code identifies follicular lymphoma grade IIIb when the primary site is not documented. It refers to an aggressive B-cell non-Hodgkin lymphoma pattern, but you should code only what the record supports.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include lymphadenopathy, systemic “B” symptoms, or biopsy results showing grade IIIb follicular lymphoma.
When to use this code
Use C82.40 when the provider documents follicular lymphoma grade IIIb and does not specify an anatomic site. It also fits situations where pathology confirms the grade but the record lacks a more precise site designation. Check documentation if another lymphoma type or site is named.
Do not use for
Do not use this code for other follicular lymphoma grades or for unspecified lymphoma without a documented grade IIIb. If the site is known and documented, code the specific site instead.
Coding tip
Verify both the grade and the absence of a documented primary site before assigning C82.40.