ICD-10 Code C88.21 – Heavy chain disease, in remission (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C88.21 – Heavy chain disease, in remission
What it is
C88.21 identifies heavy chain disease when the condition is documented as in remission. Use it when the underlying lymphoproliferative disorder is no longer active, but the diagnosis remains part of the patient’s history.
Clinical signs
Clinical features vary; refer to documentation. Heavy chain disease may be associated with abnormal immunoglobulin production, lymphoid tissue involvement, or systemic findings, but the remission status must be stated by the clinician.
When to use this code
Use C88.21 when the record clearly states heavy chain disease is in remission. This may appear in follow-up notes, oncology documentation, or problem lists that specify inactive disease. If remission is not documented, check documentation before coding.
Do not use for
Do not use this code for active heavy chain disease or for a history of the disorder without remission status. If the chart only says “history of” or is unclear, code based on the documented condition and check documentation.
Coding tip
Always verify that “in remission” is explicitly documented; do not assume remission from treatment follow-up alone.