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C84.1

C84.1Sezary disease

Non-billable headerICD-10-CM

C84.1 is a non-billable header ICD-10-CM code for sezary disease. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 inherited from the categories above C84.1

These are not written on C84.1, but they bind it: a note on a category applies to every code beneath it. Billing C84.1 with anything listed here is a denial.

Written on C84 Mature T/NK-cell lymphomas

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

Other codes that can never be billed with C84.1

These codes carry an Excludes1 note pointing at C84.1. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading C84.1 alone.

  • C82Follicular lymphoma
  • C83.0Small cell B-cell lymphoma
  • C83.3Diffuse large B-cell lymphoma
  • C86Other specified types of T/NK-cell lymphoma

Risk adjustment

C84.1 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code history

C84.1 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Code to one of these instead C84.1

11 child codes. Green means billable.

Related codes at this level

Codes that share C84. If C84.1 is not quite right, the correct code is usually one of these.

Questions about C84.1

Is C84.1 a billable ICD-10-CM code?
No. C84.1 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does C84.1 sit in the tabular list?
Neoplasms (C00-D49), in the block Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96).
What cannot be coded together with C84.1?
C84.1 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above C84.1 (C84) and apply to it just the same.
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.