ICD-10 Code C85.1 – Unspecified B-cell lymphoma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C85.1 – Unspecified B-cell lymphoma
What it is
C85.1 identifies a non-Hodgkin lymphoma of B-cell origin when the specific subtype is not documented. Use it when the record confirms B-cell lymphoma but does not name the exact histology.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include enlarged lymph nodes, unexplained weight loss, fever, night sweats, or other signs of lymphoma noted on exam or imaging.
When to use this code
Use this code when the clinician documents “B-cell lymphoma” without a more specific subtype such as diffuse large B-cell lymphoma or follicular lymphoma. It also fits when pathology or oncology notes confirm B-cell lineage but the subtype remains unspecified. If the record later identifies a specific lymphoma, code that diagnosis instead.
Do not use for
Do not use C85.1 for T-cell, Hodgkin, or other clearly specified lymphomas. If the chart names a more precise B-cell lymphoma subtype, choose that code rather than this unspecified category.
Coding tip
Query the provider when “B-cell lymphoma” is documented but the subtype is missing, because a more specific code may be available.