ICD-10 Code D72.820 – Lymphocytosis (symptomatic) (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D72.820 – Lymphocytosis (symptomatic)
What it is
D72.820 identifies symptomatic lymphocytosis, meaning an increased number of lymphocytes in the blood with documented symptoms or clinical concern. Use it when the record specifically links the abnormal finding to patient symptoms.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings may include lymphocyte-predominant leukocytosis, enlarged lymph nodes, or an illness associated with reactive or persistent lymphocytosis.
When to use this code
Use this code when the provider documents symptomatic lymphocytosis or clearly states that the elevated lymphocyte count is clinically significant. It may be appropriate when the chart ties the finding to evaluation of an underlying disorder, but the diagnosis itself remains lymphocytosis.
If the record only notes an abnormal CBC without symptoms or interpretation, check documentation before assigning this code. Code the confirmed underlying condition separately when it is established.
Do not use for
Do not use D72.820 for asymptomatic lab abnormalities or for a specific hematologic malignancy when that diagnosis is documented. Check documentation if the elevated lymphocytes are part of another confirmed disorder.
Coding tip
Assign this code only when the provider clearly documents symptomatic lymphocytosis; otherwise, query or code the more specific confirmed diagnosis.