2026 ICD-10-CM Diagnosis Code D89.84IgG4-related disease

ICD-10-CM Codes›D50–D89›D80-D89›D89

ICD-10-CM D89.84
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D89.84 is a billable ICD-10-CM diagnosis code for IgG4-related disease. 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 Immunity disorders.

Code Identity

ICD-10-CM Code
D89.84
Billable Status
Yes — Valid for Submission
Code Describes
IgG4-related disease
Short Description
IgG4-related disease
Same as the full description in the CMS dataset.
Parent Code
D89.8
Other specified disorders involving the immune mechanism, not elsewhere classified

Code Classification

ChapterD50–D89Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
SectionD80-D89Certain disorders involving the immune mechanism
CategoryD89Other disorders involving the immune mechanism, not elsewhere classified
This CodeD89.84IgG4-related disease

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Autoimmune cholangitis
  • Autoimmune hypophysitis
  • Autoimmune thyroiditis
  • IgG4-related sclerosing cholangitis
  • Immunoglobulin G4 related aortitis
  • Immunoglobulin G4 related disease
  • Immunoglobulin G4 related eosinophilic angiocentric fibrosis
  • Immunoglobulin G4 related hypophysitis
  • Immunoglobulin G4 related kidney disease
  • Immunoglobulin G4 related ophthalmic disease
  • Immunoglobulin G4 related pachymeningitis
  • Immunoglobulin G4 related periaortitis
  • Immunoglobulin G4 related submandibular gland disease
  • Immunoglobulin G4 related thyroid disease
  • Pachymeningitis
  • Sclerosing cholangitis
  • Secondary sclerosing cholangitis
  • Sialoadenitis of the submandibular gland

Tabular List NotesGuidance

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

Inclusion Terms

  • Immunoglobulin G4-related disease

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.

    • Disease, diseased
      • IgG4-related

Clinical ClassificationClinical

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

CCSR BLD008
Immunity disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Autoimmune Hypophysitis

    immune-mediated inflammation of the pituitary gland often associated with other autoimmune diseases (e.g., hashimoto disease; graves disease; and addison disease).

  • Autoimmune Hypophysitis|Lymphocytic Hypophysitis

    an autoimmune condition affecting the pituitary gland, characterized by lymphocytic infiltration, commonly presenting with pituitary hormone deficiencies.

  • Grade 1 Hypophysitis, CTCAE|Grade 1 Hypophysitis

    asymptomatic or mild symptoms; clinical or diagnostic observations only; intervention not indicated

  • Grade 2 Hypophysitis, CTCAE|Grade 2 Hypophysitis

    moderate; minimal, local or noninvasive intervention indicated; limiting age-appropriate instrumental adl

  • Grade 3 Hypophysitis, CTCAE|Grade 3 Hypophysitis

    severe or medically significant but not immediately life-threatening; hospitalization or prolongation of existing hospitalization indicated; limiting self care adl

  • Grade 4 Hypophysitis, CTCAE|Grade 4 Hypophysitis

    life-threatening consequences; urgent intervention indicated

  • Grade 5 Hypophysitis, CTCAE|Grade 5 Hypophysitis

    death

  • Hypophysitis

    an inflammatory process in the pituitary gland.

  • Hypophysitis, CTCAE|Hypophysitis

    a disorder characterized by inflammation and cellular infiltration of the pituitary gland.

  • Lymphocytic Neurohypophysitis

    an autoimmune condition affecting the posterior pituitary gland, which is characterized by lymphocytic infiltration, and which often presents as diabetes insipidus.

Code History & ChangesHistory

Replacement D89.84 replaces the following previously assigned code(s):

  • D89.89 - Oth disrd involving the immune mechanism, NEC
FY 2024AddedAdded to the ICD-10-CM code setEffective October 1, 2023.
FY 2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D89.84Overview

Is D89.84 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report IgG4-related disease on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D89.84 group to?

When IgG4-related disease 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.

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.