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ICD-10-CM 2027

ICD-10 code for lymphoid leukemia

C91.9

Lymphoid leukemia, unspecified

Header — needs a more specific code

From the official ICD-10-CM alphabetic index entry “Leukemia, leukemic › lymphoid”. Page updated September 29, 2026.

About coding lymphoid leukemia

The ICD-10-CM code for lymphoid leukemia is C91.9 (Lymphoid leukemia, unspecified). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on C91.9.

Within C91, choose C91.9 (unspecified) only when documentation doesn't support a more specific option: acute lymphoblastic leukemia [ALL] (C91.0), chronic lymphocytic leukemia of B-cell type (C91.1), Prolymphocytic leukemia of B-cell type (C91.3), Hairy cell leukemia (C91.4), adult T-cell lymphoma/leukemia (HTLV-1-associated) (C91.5), Prolymphocytic leukemia of T-cell type (C91.6), mature B-cell leukemia Burkitt-type (C91.A) and other lymphoid leukemia (C91.Z).

To report this condition, pick the subcode that matches the documentation: C91.90 (not having achieved remission), C91.91 (in remission) and C91.92 (in relapse).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

More specific lymphoid leukemia codes (official index)

  • specified NEC C91.Z — Other lymphoid leukemia

Common questions about lymphoid leukemia ICD-10 codes

What is the ICD-10 code for lymphoid leukemia?

C91.9 — Lymphoid leukemia, unspecified (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: C91.Z.

Is C91.9 billable?

No. C91.9 is a header code. Report one of its more specific subcodes instead.