2026 ICD-10-CM Diagnosis Code I88.9Nonspecific lymphadenitis, unspecified

ICD-10-CM Codes›I00–I99›I80-I89›I88

ICD-10-CM I88.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I88.9 is a billable ICD-10-CM diagnosis code for nonspecific lymphadenitis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 814 through 816. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified diseases of veins and lymphatics.

Code Identity

ICD-10-CM Code
I88.9
Billable Status
Yes — Valid for Submission
Code Describes
Nonspecific lymphadenitis, unspecified
Short Description
Nonspecific lymphadenitis, unspecified
Same as the full description in the CMS dataset.
Parent Code
I88
Nonspecific lymphadenitis

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI80-I89Diseases of veins, lymphatic vessels and lymph nodes, not elsewhere classified
CategoryI88Nonspecific lymphadenitis
This CodeI88.9Nonspecific lymphadenitis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Aphthous ulcer of mouth
  • Cervical lymphadenitis
  • Complex multigenic autoinflammatory syndrome
  • Granulomatous lymphadenitis
  • Jugular lymphadenopathy
  • Lymphadenitis
  • Lymphadenitis caused by Toxoplasma gondii
  • PFAPA syndrome
  • Recurrent aphthous ulcer
  • Recurrent ulcer of mouth
  • Tonsillar adenitis

Tabular List NotesGuidance

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

Inclusion Terms

  • Lymphadenitis NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Adenitis
      • axillary
    • Adenitis
      • cervical
    • Adenitis
      • groin
    • Adenitis
      • inguinal
    • Adenitis
      • lymph gland or node, except mesenteric
    • Infiltrate, infiltration
      • lymphatic
        • gland
    • Lymphadenitis
    • Lymphadenitis
      • any site, except mesenteric

Clinical ClassificationClinical

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

CCSR CIR039
Other specified diseases of veins and lymphatics
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Histiocytic Necrotizing Lymphadenitis

    development of lesions in the lymph node characterized by infiltration of the cortex or paracortex by large collections of proliferating histiocytes and complete or, more often, incomplete necrosis of lymphoid tissue.

  • Lymphadenitis

    inflammation of the lymph nodes.

  • Mesenteric Lymphadenitis

    inflammation of lymph nodes in the mesentery.

  • Tuberculosis, Lymph Node

    infection of the lymph nodes by tuberculosis. tuberculous infection of the cervical lymph nodes is scrofula.

  • Cervical Lymphadenitis

    inflammation of the cervical lymph nodes.

Patient EducationClinical

Lymphatic Diseases

The lymphatic system is a network of tissues and organs. It is made up of:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert I88.9 to ICD-9-CMHistory

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

ICD-9-CM
289.3 Lymphadenitis NOS
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 I88.9Overview

Is I88.9 (Nonspecific lymphadenitis) a billable code?

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

What MS-DRG does I88.9 group to?

When nonspecific lymphadenitis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 814, 815, 816, with relative weights from 0.6320 to 2.1267 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I88.9?

Under the General Equivalence Mappings, nonspecific lymphadenitis, unspecified converts to ICD-9-CM 289.3 (lymphadenitis NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.