2026 ICD-10-CM Diagnosis Code C84Mature T/NK-cell lymphomas

ICD-10-CM Codes›C00–D49›C81-C96›C84

ICD-10-CM C84
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C84 is a non-billable ICD-10-CM category code for mature T/NK-cell lymphomas, so it cannot be submitted on claims. Use a more specific code from this category instead, such as C84.00, C84.01, C84.02, and C84.03.

Code Identity

ICD-10-CM Code
C84
Billable Status
No — Non-Billable Category
Code Describes
Mature T/NK-cell lymphomas
Chapter
C81-C96
Malignant neoplasms of lymphoid, hematopoietic and related tissue

Code Classification

ChapterC00–D49Neoplasms
SectionC81-C96Malignant neoplasms of lymphoid, hematopoietic and related tissue
CategoryC84Mature T/NK-cell lymphomas
This CodeC84Mature T/NK-cell lymphomas

Specific Coding for Mature T/NK-cell lymphomasOverview

Non-specific codes like C84 require more characters. Use one of these billable codes instead:

  • C84.0 for Mycosis fungoides

  • Use C84.00 for Mycosis fungoides, unspecified site

  • Use C84.01 for Mycosis fungoides, lymph nodes of head, face, and neck

  • Use C84.02 for Mycosis fungoides, intrathoracic lymph nodes

  • Use C84.03 for Mycosis fungoides, intra-abdominal lymph nodes

  • Use C84.04 for Mycosis fungoides, lymph nodes of axilla and upper limb

  • Use C84.05 for Mycosis fungoides, lymph nodes of inguinal region and lower limb

  • Use C84.06 for Mycosis fungoides, intrapelvic lymph nodes

  • Use C84.07 for Mycosis fungoides, spleen

  • Use C84.08 for Mycosis fungoides, lymph nodes of multiple sites

  • Use C84.09 for Mycosis fungoides, extranodal and solid organ sites

  • Use C84.0A for Mycosis fungoides, in remission

  • C84.1 for Sezary disease

  • Use C84.10 for Sezary disease, unspecified site

  • Use C84.11 for Sezary disease, lymph nodes of head, face, and neck

  • Use C84.12 for Sezary disease, intrathoracic lymph nodes

  • Use C84.13 for Sezary disease, intra-abdominal lymph nodes

  • Use C84.14 for Sezary disease, lymph nodes of axilla and upper limb

  • Use C84.15 for Sezary disease, lymph nodes of inguinal region and lower limb

  • Use C84.16 for Sezary disease, intrapelvic lymph nodes

  • Use C84.17 for Sezary disease, spleen

  • Use C84.18 for Sezary disease, lymph nodes of multiple sites

  • Use C84.19 for Sezary disease, extranodal and solid organ sites

  • Use C84.1A for Sezary disease, in remission

  • C84.4 for Peripheral T-cell lymphoma, not elsewhere classified

  • Use C84.40 for Peripheral T-cell lymphoma, not elsewhere classified, unspecified site

  • Use C84.41 for Peripheral T-cell lymphoma, not elsewhere classified, lymph nodes of head, face, and neck

  • Use C84.42 for Peripheral T-cell lymphoma, not elsewhere classified, intrathoracic lymph nodes

  • Use C84.43 for Peripheral T-cell lymphoma, not elsewhere classified, intra-abdominal lymph nodes

  • Use C84.44 for Peripheral T-cell lymphoma, not elsewhere classified, lymph nodes of axilla and upper limb

  • Use C84.45 for Peripheral T-cell lymphoma, not elsewhere classified, lymph nodes of inguinal region and lower limb

  • Use C84.46 for Peripheral T-cell lymphoma, not elsewhere classified, intrapelvic lymph nodes

  • Use C84.47 for Peripheral T-cell lymphoma, not elsewhere classified, spleen

  • Use C84.48 for Peripheral T-cell lymphoma, not elsewhere classified, lymph nodes of multiple sites

  • Use C84.49 for Peripheral T-cell lymphoma, not elsewhere classified, extranodal and solid organ sites

  • Use C84.4A for Peripheral T-cell lymphoma, not elsewhere classified, in remission

  • C84.6 for Anaplastic large cell lymphoma, ALK-positive

  • Use C84.60 for Anaplastic large cell lymphoma, ALK-positive, unspecified site

  • Use C84.61 for Anaplastic large cell lymphoma, ALK-positive, lymph nodes of head, face, and neck

  • Use C84.62 for Anaplastic large cell lymphoma, ALK-positive, intrathoracic lymph nodes

  • Use C84.63 for Anaplastic large cell lymphoma, ALK-positive, intra-abdominal lymph nodes

  • Use C84.64 for Anaplastic large cell lymphoma, ALK-positive, lymph nodes of axilla and upper limb

  • Use C84.65 for Anaplastic large cell lymphoma, ALK-positive, lymph nodes of inguinal region and lower limb

  • Use C84.66 for Anaplastic large cell lymphoma, ALK-positive, intrapelvic lymph nodes

  • Use C84.67 for Anaplastic large cell lymphoma, ALK-positive, spleen

  • Use C84.68 for Anaplastic large cell lymphoma, ALK-positive, lymph nodes of multiple sites

  • Use C84.69 for Anaplastic large cell lymphoma, ALK-positive, extranodal and solid organ sites

  • Use C84.6A for Anaplastic large cell lymphoma, ALK-positive, in remission

  • C84.7 for Anaplastic large cell lymphoma, ALK-negative

  • Use C84.70 for Anaplastic large cell lymphoma, ALK-negative, unspecified site

  • Use C84.71 for Anaplastic large cell lymphoma, ALK-negative, lymph nodes of head, face, and neck

  • Use C84.72 for Anaplastic large cell lymphoma, ALK-negative, intrathoracic lymph nodes

  • Use C84.73 for Anaplastic large cell lymphoma, ALK-negative, intra-abdominal lymph nodes

  • Use C84.74 for Anaplastic large cell lymphoma, ALK-negative, lymph nodes of axilla and upper limb

  • Use C84.75 for Anaplastic large cell lymphoma, ALK-negative, lymph nodes of inguinal region and lower limb

  • Use C84.76 for Anaplastic large cell lymphoma, ALK-negative, intrapelvic lymph nodes

  • Use C84.77 for Anaplastic large cell lymphoma, ALK-negative, spleen

  • Use C84.78 for Anaplastic large cell lymphoma, ALK-negative, lymph nodes of multiple sites

  • Use C84.79 for Anaplastic large cell lymphoma, ALK-negative, extranodal and solid organ sites

  • Use C84.7A for Anaplastic large cell lymphoma, ALK-negative, breast

  • Use C84.7B for Anaplastic large cell lymphoma, ALK-negative, in remission

  • C84.9 for Mature T/NK-cell lymphomas, unspecified

  • Use C84.90 for Mature T/NK-cell lymphomas, unspecified, unspecified site

  • Use C84.91 for Mature T/NK-cell lymphomas, unspecified, lymph nodes of head, face, and neck

  • Use C84.92 for Mature T/NK-cell lymphomas, unspecified, intrathoracic lymph nodes

  • Use C84.93 for Mature T/NK-cell lymphomas, unspecified, intra-abdominal lymph nodes

  • Use C84.94 for Mature T/NK-cell lymphomas, unspecified, lymph nodes of axilla and upper limb

  • Use C84.95 for Mature T/NK-cell lymphomas, unspecified, lymph nodes of inguinal region and lower limb

  • Use C84.96 for Mature T/NK-cell lymphomas, unspecified, intrapelvic lymph nodes

  • Use C84.97 for Mature T/NK-cell lymphomas, unspecified, spleen

  • Use C84.98 for Mature T/NK-cell lymphomas, unspecified, lymph nodes of multiple sites

  • Use C84.99 for Mature T/NK-cell lymphomas, unspecified, extranodal and solid organ sites

  • Use C84.9A for Mature T/NK-cell lymphomas, unspecified, in remission

  • C84.A for Cutaneous T-cell lymphoma, unspecified

  • Use C84.A0 for Cutaneous T-cell lymphoma, unspecified, unspecified site

  • Use C84.A1 for Cutaneous T-cell lymphoma, unspecified lymph nodes of head, face, and neck

  • Use C84.A2 for Cutaneous T-cell lymphoma, unspecified, intrathoracic lymph nodes

  • Use C84.A3 for Cutaneous T-cell lymphoma, unspecified, intra-abdominal lymph nodes

  • Use C84.A4 for Cutaneous T-cell lymphoma, unspecified, lymph nodes of axilla and upper limb

  • Use C84.A5 for Cutaneous T-cell lymphoma, unspecified, lymph nodes of inguinal region and lower limb

  • Use C84.A6 for Cutaneous T-cell lymphoma, unspecified, intrapelvic lymph nodes

  • Use C84.A7 for Cutaneous T-cell lymphoma, unspecified, spleen

  • Use C84.A8 for Cutaneous T-cell lymphoma, unspecified, lymph nodes of multiple sites

  • Use C84.A9 for Cutaneous T-cell lymphoma, unspecified, extranodal and solid organ sites

  • Use C84.AA for Cutaneous T-cell lymphoma, unspecified, in remission

  • C84.Z for Other mature T/NK-cell lymphomas

  • Use C84.Z0 for Other mature T/NK-cell lymphomas, unspecified site

  • Use C84.Z1 for Other mature T/NK-cell lymphomas, lymph nodes of head, face, and neck

  • Use C84.Z2 for Other mature T/NK-cell lymphomas, intrathoracic lymph nodes

  • Use C84.Z3 for Other mature T/NK-cell lymphomas, intra-abdominal lymph nodes

  • Use C84.Z4 for Other mature T/NK-cell lymphomas, lymph nodes of axilla and upper limb

  • Use C84.Z5 for Other mature T/NK-cell lymphomas, lymph nodes of inguinal region and lower limb

  • Use C84.Z6 for Other mature T/NK-cell lymphomas, intrapelvic lymph nodes

  • Use C84.Z7 for Other mature T/NK-cell lymphomas, spleen

  • Use C84.Z8 for Other mature T/NK-cell lymphomas, lymph nodes of multiple sites

  • Use C84.Z9 for Other mature T/NK-cell lymphomas, extranodal and solid organ sites

  • Use C84.ZA for Other mature T/NK-cell lymphomas, in remission

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • personal history of non-Hodgkin lymphoma Z85.72

Patient EducationClinical

Lymphoma

Lymphoma is a cancer of a part of the immune system called the lymph system. There are many types of lymphoma. One type is Hodgkin disease. The rest are called non-Hodgkin lymphomas.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C84Overview

Is C84 (Mature T/NK-cell lymphomas) a billable code?

No. This is a category header that groups the codes for mature T/NK-cell lymphomas, and headers cannot be submitted on claims. Claims for mature T/NK-cell lymphomas need a more specific code from this category, such as C84.00, C84.01, and C84.02.