C84 – Mature T/NK-cell lymphomas

ICD-10-CM 2027 diagnosis code · Malignant neoplasms of lymphoid, hematopoietic and related tissue

Non-billable header

ICD-10-CM code C84

Code: C84 (claims format: C84)
Description: Mature T/NK-cell lymphomas
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 2. Neoplasms (C00-D49)
Block: C81-C96 Malignant neoplasms of lymphoid, hematopoietic and related tissue

Billable codes under C84

C84 is a header code and cannot be used on claims. Choose the most specific code:

C84.0 – Mycosis fungoidesHeader (more codes below)
C84.1 – Sezary diseaseHeader (more codes below)
C84.4 – Peripheral T-cell lymphoma, not elsewhere classifiedHeader (more codes below)
C84.6 – Anaplastic large cell lymphoma, ALK-positiveHeader (more codes below)
C84.7 – Anaplastic large cell lymphoma, ALK-negativeHeader (more codes below)
C84.A – Cutaneous T-cell lymphoma, unspecifiedHeader (more codes below)
C84.Z – Other mature T/NK-cell lymphomasHeader (more codes below)
C84.9 – Mature T/NK-cell lymphomas, unspecifiedHeader (more codes below)

Notes for C84

Excludes1 (not coded here):

personal history of non-Hodgkin lymphoma (Z85.72)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block C81-C96

Excludes2 (not included here):

Kaposi's sarcoma of lymph nodes (C46.3)
secondary and unspecified neoplasm of lymph nodes (C77.-)
secondary neoplasm of bone marrow (C79.52)
secondary neoplasm of spleen (C78.89)

Frequently asked questions

What is ICD-10 code C84?

C84 is the ICD-10-CM code for mature T/NK-cell lymphomas, in the block C81-C96 (Malignant neoplasms of lymphoid, hematopoietic and related tissue).

Is C84 a billable code?

No. C84 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.