ICD-10-CM 2027 diagnosis code
C84.1Sezary disease
C84.1 is a header code, so it can't be reported by itself. Choose one of the 11 more specific codes beneath it.
Looking up by condition? See ICD-10 code for Sézary disease.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About C84.1
C84.1 is the ICD-10-CM diagnosis code for Sezary disease. It belongs to category C84 (mature T/NK-cell lymphomas), block C81-C96 (malignant neoplasms of lymphoid, hematopoietic and related tissue) and chapter 2 (neoplasms). It is a header code, so it can't be reported by itself; one of its 11 subcodes must be used instead.
Within C84 (mature T/NK-cell lymphomas), C84.1 is specifically for Sezary disease. Related codes cover mycosis fungoides (C84.0), peripheral T-cell lymphoma, not elsewhere classified (C84.4), Anaplastic large cell lymphoma, ALK-positive (C84.6), Anaplastic large cell lymphoma, ALK-negative (C84.7), unspecified (C84.9), cutaneous T-cell lymphoma, unspecified (C84.A) and other mature T/NK-cell lymphomas (C84.Z).
To report this condition, pick the subcode that matches the documentation: C84.10 (unspecified site), C84.11 (lymph nodes of head, face, and neck), C84.12 (intrathoracic lymph nodes), C84.13 (intra-abdominal lymph nodes), C84.14 (lymph nodes of axilla and upper limb), C84.15 (lymph nodes of inguinal region and lower limb), C84.16 (intrapelvic lymph nodes), C84.17 (spleen) and 3 more.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Specific codes under C84.1
- C84.10Sezary disease, unspecified siteBillable
- C84.11Sezary disease, lymph nodes of head, face, and neckBillable
- C84.12Sezary disease, intrathoracic lymph nodesBillable
- C84.13Sezary disease, intra-abdominal lymph nodesBillable
- C84.14Sezary disease, lymph nodes of axilla and upper limbBillable
- C84.15Sezary disease, lymph nodes of inguinal region and lower limbBillable
- C84.16Sezary disease, intrapelvic lymph nodesBillable
- C84.17Sezary disease, spleenBillable
- C84.18Sezary disease, lymph nodes of multiple sitesBillable
- C84.19Sezary disease, extranodal and solid organ sitesBillable
- C84.1ASezary disease, in remissionBillable
Notes that apply from higher levels
Instructions written at a parent level also apply to C84.1.
› From C84 Mature T/NK-cell lymphomas
- personal history of non-Hodgkin lymphoma (Z85.72)
Broader instructions also apply from C81-C96 Malignant neoplasms of lymphoid, hematopoietic and related tissue and Chapter 2: Neoplasms.
Alphabetic index entries
2 entriesTerms in the official ICD-10-CM index that lead to C84.1.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about C84.1
Is C84.1 billable?
- No. C84.1 is a header code. Report one of its more specific subcodes instead.