ICD10BillableValid for clinical use

ICD-10 Code C84.90: Mature T/NK-cell lymphomas, unspecified, unspecified site

C84.90 is a billable ICD-10 diagnosis code used to classify Mature T/NK-cell lymphomas, unspecified, unspecified site in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).

When is it used?

  • May be used when a clinician documents mature t/nk-cell lymphomas, unspecified, unspecified site in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
2Neoplasms (C00-D49)
block
C00-C96Malignant neoplasms
block
C81-C96Malignant neoplasms of lymphoid, hematopoietic and related tissue
category
C84Mature T/NK-cell lymphomas
category
C84.9Mature T/NK-cell lymphomas, unspecified
currentC84.9

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

OncologistGeneral Physician

Sibling codes

C84.91Mature T/NK-cell lymphomas, unspecified, lymph nodes of head, face, and neckbillableC84.92Mature T/NK-cell lymphomas, unspecified, intrathoracic lymph nodesbillableC84.93Mature T/NK-cell lymphomas, unspecified, intra-abdominal lymph nodesbillableC84.94Mature T/NK-cell lymphomas, unspecified, lymph nodes of axilla and upper limbbillableC84.95Mature T/NK-cell lymphomas, unspecified, lymph nodes of inguinal region and lower limbbillableC84.96Mature T/NK-cell lymphomas, unspecified, intrapelvic lymph nodesbillableC84.97Mature T/NK-cell lymphomas, unspecified, spleenbillableC84.98Mature T/NK-cell lymphomas, unspecified, lymph nodes of multiple sitesbillableC84.99Mature T/NK-cell lymphomas, unspecified, extranodal and solid organ sitesbillableC84.9AMature T/NK-cell lymphomas, unspecified, in remissionbillable

Coding guidelines

Common synonyms

Mature T/NK-cell lymphomas, unspecified, unspecified siteMature T/NK-cell lymphomas, unspecified

Frequently asked questions

Code details

CodeC84.90
SystemICD10
Display nameMature T/NK-cell lymphomas, unspecified, unspecified site
ChapterNeoplasms (C00-D49)
BlockMalignant neoplasms of lymphoid, hematopoietic and related tissue

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code C84.90 for Mature T/NK-cell lymphomas, unspecified, unspecified site | HealthAssure