Skip to content

C84.1 ICD-10-CM Code: Sezary disease

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96)

C84.1

Header CodeICD-10-CMOfficial ICD-10-CMCodebook guidance

Sezary disease

Sezary disease

CMS-HCC V28

0

0

RAF 0

CMS-HCC V24

0

0

RAF 0

ACA/HHS

0

0

RAF 0

ESRD/PACE

0

0

RAF 0

RXHCC

0

0

RAF 0

Code Trumping

Basket needed

Code Book Path

Official
C84Mature T/NK-cell lymphomas
C84.1Sezary disease

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for C84.1 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C84.1 in this effective period.

Related Child Codes

Official
C84.10Sezary disease, unspecified site
C84.11Sezary disease, lymph nodes of head, face, and neck
C84.12Sezary disease, intrathoracic lymph nodes
C84.13Sezary disease, intra-abdominal lymph nodes
C84.14Sezary disease, lymph nodes of axilla and upper limb

Includes

Official

ICD-10-CM does not list Includes notes for C84.1 in this effective period.

Excludes 1

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

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C84.1 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C84.1 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C84.1 in this effective period.

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

What This Code Means

C84.1 is the ICD-10-CM diagnosis code for sezary disease. C84.1 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lymphoid, hematopoietic and related tissue (c81-c96).

Header codes like C84.1 cannot be reported on claims directly, they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at C84.1's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for C84.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Child Codes

Code Hierarchy

Open C84.1 in the Interactive Encoder

See full code details, coding tips, HCC mappings, and related codes in the interactive encoder. Pro includes 14 days to try the full workflow.