2026 ICD-10-CM Diagnosis Code C86.00Extranodal NK/T-cell lymphoma, nasal type not having achieved remission

ICD-10-CM Codes›C00–D49›C81-C96›C86

ICD-10-CM C86.00
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C86.00 is a billable ICD-10-CM diagnosis code for extranodal NK/T-cell lymphoma, nasal type not having achieved remission. 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, 974 through 976. 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 70 closely related codes. Coders also document this condition as angiocentric NK/T-cell malignant lymphoma involving skin. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Non-Hodgkin lymphoma.

For Medicare Advantage risk adjustment, C86.00 maps to CMS-HCC Category 20 (Lung and Other Severe Cancers) under the V28 model, adding a risk factor of about 1.136 for a community, non-dual, aged beneficiary in payment year 2026.

Code Identity

ICD-10-CM Code
C86.00
Billable Status
Yes — Valid for Submission
Code Describes
Extranodal NK/T-cell lymphoma, nasal type not having achieved remission
Short Description
Extranodal NK/T-cell lymphoma, nasal type not remission
Parent Code
C86.0
Extranodal NK/T-cell lymphoma, nasal type

Code Classification

ChapterC00–D49Neoplasms
SectionC81-C96Malignant neoplasms of lymphoid, hematopoietic and related tissue
CategoryC86Other specified types of T/NK-cell lymphoma
This CodeC86.00Extranodal NK/T-cell lymphoma, nasal type not having achieved remission

Medicare Risk Adjustment (HCC)Billing

C86.00 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.

CMS-HCC V28 Category (Payment Model)
HCC 20— Lung and Other Severe Cancers
Payment HCC · PY 2026 one of 233 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+1.136
community, non-dual, aged · ranges 0.672–1.214 across segments
Hierarchy
Superseded by HCC 17, HCC 18, and HCC 19
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 10
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 10 · ESRD (V21): HCC 10 · ESRD (V24): HCC 10
ESRD V21 weights: 0.136 dialysis, 0.451–0.668 functioning graft · ESRD V24 weights: 0.111 dialysis, 0.467–0.780 functioning graft
Part D (RxHCC)
RxHCC 21 — Lymphomas and Other Hematologic Cancers
also risk-adjusts in the Part D prescription drug model (V08)

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.

  • Angiocentric NK/T-cell malignant lymphoma involving skin
  • Extranodal NK/T-cell lymphoma, nasal type

Tabular List NotesGuidance

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

Inclusion Terms

  • Extranodal NK/T-cell lymphoma, nasal type NOS
  • Extranodal NK/T-cell lymphoma, nasal type with failed remission

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO058
Non-Hodgkin lymphoma
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement C86.00 replaces the following previously assigned code(s):

  • C86.0 - Extranodal NK/T-cell lymphoma, nasal type
FY 2025AddedAdded to the ICD-10-CM code setEffective October 1, 2024.
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C86.00Overview

Is C86.00 (Extranodal NK/T-cell lymphoma, nasal type) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report extranodal NK/T-cell lymphoma, nasal type not having achieved remission on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C86.00 group to?

When extranodal NK/T-cell lymphoma, nasal type not having achieved remission 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, 974, 975, 976, with relative weights from 0.8945 to 5.8648 depending on complications. Higher weights mean higher Medicare reimbursement.

Is C86.00 a CC or MCC?

CMS lists C86.00 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 70 closely related codes in its exclusion list.

What HCC is C86.00?

C86.00 (extranodal NK/T-cell lymphoma, nasal type not having achieved remission) maps to CMS-HCC Category 20 (Lung and Other Severe Cancers), commonly written as HCC 20, 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 21.

Does C86.00 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, C86.00 adds a risk adjustment factor of about 1.136 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.672 to 1.214 depending on the payment segment). A more severe related category (HCC 17, HCC 18, and HCC 19) supersedes it when both are reported. See the full factor table on the HCC 20 category page.