2026 ICD-10-CM Diagnosis Code C84.11Sezary disease, lymph nodes of head, face, and neck
ICD-10-CM Codes›C00–D49›C81-C96›C84
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 17
- Chronic Condition
C84.11 is a billable ICD-10-CM diagnosis code for sezary disease, lymph nodes of head, face, and neck. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 11 through 13, 820 through 825, 840 through 842. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 22 closely related codes. Coders also document this condition as sézary disease of lymph nodes of head. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Non-Hodgkin lymphoma.
For Medicare Advantage risk adjustment, C84.11 maps to CMS-HCC Category 17 (Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic) under the V28 model, adding a risk factor of about 4.209 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C84.11 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Sézary disease of lymph nodes of head
- Sézary disease of lymph nodes of head and neck
- Sézary disease of lymph nodes of neck
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.
Convert C84.11 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C84.11Overview
What is the ICD-10 code for sezary disease, lymph nodes of head, face, and neck?
The ICD-10-CM code for sezary disease, lymph nodes of head, face, and neck is C84.11 (sometimes written as C8411). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is C84.11 (Sezary disease) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report sezary disease, lymph nodes of head, face, and neck on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C84.11 group to?
When sezary disease, lymph nodes of head, face, and neck is the principal diagnosis on an inpatient stay, it groups to MS-DRG 11, 12, 13, 820, 821, 822, 823, 824, 825, 840, 841, 842, with relative weights from 1.0104 to 5.8648 depending on complications. Higher weights mean higher Medicare reimbursement.
Is C84.11 a CC or MCC?
CMS lists C84.11 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 22 closely related codes in its exclusion list.
What is the ICD-9 equivalent of C84.11?
Under the General Equivalence Mappings, sezary disease, lymph nodes of head, face, and neck converts to ICD-9-CM 202.21 (Sezary's disease head). The mapping is a direct match.
What HCC is C84.11?
C84.11 (sezary disease, lymph nodes of head, face, and neck) maps to CMS-HCC Category 17 (Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic), commonly written as HCC 17, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 10 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 19.
Does C84.11 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C84.11 adds a risk adjustment factor of about 4.209 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 1.952 to 4.235 depending on the payment segment). HCC 17 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 17 category page.
