2026 ICD-10-CM Diagnosis Code R59.1Generalized enlarged lymph nodes

ICD-10-CM Codes›R00–R99›R50-R69›R59

ICD-10-CM R59.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R59.1 is a billable ICD-10-CM diagnosis code for generalized enlarged lymph nodes. 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. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other general signs and symptoms.

Code Identity

ICD-10-CM Code
R59.1
Billable Status
Yes — Valid for Submission
Code Describes
Generalized enlarged lymph nodes
Short Description
Generalized enlarged lymph nodes
Same as the full description in the CMS dataset.
Parent Code
R59
Enlarged lymph nodes

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR50-R69General symptoms and signs
CategoryR59Enlarged lymph nodes
This CodeR59.1Generalized enlarged lymph nodes

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Deep lymphadenopathy
  • Fibrotic lymphadenopathy
  • Finding of lymph node
  • Generalized enlarged lymph nodes
  • Lymphadenopathy
  • Lymphadenopathy co-occurrent with human immunodeficiency virus infection
  • Paravesicular lymphadenopathy
  • Persistent generalized lymphadenopathy
  • Persistent generalized lymphadenopathy caused by human immunodeficiency virus
  • Postvesicular lymphadenopathy
  • Reactive lymphadenopathy
  • Superficial lymphadenopathy
  • Swelling of lymphoreticular structure
  • Tenderness of lymph node
  • Tenderness of lymphoreticular structure
  • Tethering of lymph node

Tabular List NotesGuidance

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

Inclusion Terms

  • Lymphadenopathy 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.

    • Adenopathy(lymph gland)
      • generalized
    • Enlargement, enlarged
      • lymph gland or node
        • generalized
    • Hypertrophy, hypertrophic
      • gland, glandular
        • generalized
    • Hypertrophy, hypertrophic
      • lymph, lymphatic gland
        • generalized
    • Lymphadenopathy(generalized)
    • Lymphadenosis
    • Swelling(of)
      • glands
        • generalized

Clinical ClassificationClinical

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

CCSR SYM016
Other general signs and symptoms
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • AIDS-Related Complex

    a prodromal phase of infection with the human immunodeficiency virus (hiv). laboratory criteria separating aids-related complex (arc) from aids include elevated or hyperactive b-cell humoral immune responses, compared to depressed or normal antibody reactivity in aids; follicular or mixed hyperplasia in arc lymph nodes, leading to lymphocyte degeneration and depletion more typical of aids; evolving succession of histopathological lesions such as localization of kaposi's sarcoma, signaling the transition to the full-blown aids.

  • HIV

    human immunodeficiency virus. a non-taxonomic and historical term referring to any of two species, specifically hiv-1 and/or hiv-2. prior to 1986, this was called human t-lymphotropic virus type iii/lymphadenopathy-associated virus (htlv-iii/lav). from 1986-1990, it was an official species called hiv. since 1991, hiv was no longer considered an official species name; the two species were designated hiv-1 and hiv-2.

  • HIV Antibodies

    antibodies reactive with hiv antigens.

  • HIV Antigens

    antigens associated with specific proteins of the human adult t-cell immunodeficiency virus (hiv); also called htlv-iii-associated and lymphadenopathy-associated virus (lav) antigens.

  • Immunoblastic Lymphadenopathy

    a disorder characterized by proliferation of arborizing small vessels, prominent immunoblastic proliferations and amorphous acidophilic interstitial material. clinical manifestations include fever, sweats, weight loss, generalized lymphadenopathy and frequently hepatosplenomegaly.

  • Lymphadenopathy

    disease of lymph nodes which are abnormal in size, number or consistency.

  • Spotted Fever Group Rickettsiosis

    a group of arthropod-borne diseases caused by spotted fever bio-group members of rickettsia. they are characterized by fever, headache, and petechial (spotted) rash.

  • Lymph Nodes

    they are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.

  • Rickettsia

    a genus of gram-negative, aerobic, rod-shaped bacteria often surrounded by a protein microcapsular layer and slime layer. the natural cycle of its organisms generally involves a vertebrate and an invertebrate host. species of the genus are the etiological agents of human diseases, such as typhus.

Convert R59.1 to ICD-9-CMHistory

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

ICD-9-CM
785.6 Enlargement lymph nodes
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 R59.1Overview

Is R59.1 (Enlarged lymph nodes) a billable code?

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

What MS-DRG does R59.1 group to?

When generalized enlarged lymph nodes 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.

Can R59.1 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the generalized enlarged lymph nodes is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R59.1?

Under the General Equivalence Mappings, generalized enlarged lymph nodes converts to ICD-9-CM 785.6 (enlargement lymph nodes). 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.