2026 ICD-10-CM Diagnosis Code C83.00Small cell B-cell lymphoma, unspecified site

ICD-10-CM Codes›C00–D49›C81-C96›C83

ICD-10-CM C83.00
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C83.00 is a billable ICD-10-CM diagnosis code for small cell B-cell lymphoma, unspecified site. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 820 through 825, 840 through 842, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Non-Hodgkin lymphoma.

Code Identity

ICD-10-CM Code
C83.00
Billable Status
Yes — Valid for Submission
Code Describes
Small cell B-cell lymphoma, unspecified site
Short Description
Small cell B-cell lymphoma, unspecified site
Same as the full description in the CMS dataset.
Parent Code
C83.0
Small cell B-cell lymphoma

Code Classification

ChapterC00–D49Neoplasms
SectionC81-C96Malignant neoplasms of lymphoid, hematopoietic and related tissue
CategoryC83Non-follicular lymphoma
This CodeC83.00Small cell B-cell lymphoma, unspecified site

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Diffuse low grade B-cell lymphoma
  • Diffuse non-Hodgkin's lymphoma, small cell
  • Lymphoplasmacytic lymphoma without immunoglobulin M production
  • Malignant lymphoma - lymphoplasmacytic
  • Malignant lymphoma - small lymphocytic
  • Marginal zone lymphoma
  • Monocytoid B-cell lymphoma
  • Nodal marginal zone B-cell lymphoma
  • Pediatric nodal marginal zone B cell lymphoma
  • Primary cutaneous B-cell lymphoma
  • Primary cutaneous immunocytoma
  • Primary cutaneous marginal zone B-cell lymphoma
  • Small lymphocytic B-cell lymphoma involving skin

Clinical ClassificationClinical

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

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

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 C83.00 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
200.80 Oth varn unsp xtrndl org
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C83.00Overview

Is C83.00 (Small cell B-cell lymphoma) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report small cell B-cell lymphoma, unspecified site on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C83.00 group to?

When small cell B-cell lymphoma, unspecified site is the principal diagnosis on an inpatient stay, it groups to MS-DRG 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.

What is the ICD-9 equivalent of C83.00?

Under the General Equivalence Mappings, small cell B-cell lymphoma, unspecified site converts to ICD-9-CM 200.80 (oth varn unsp xtrndl org). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.