2026 ICD-10-CM Diagnosis Code E23.3Hypothalamic dysfunction, not elsewhere classified

ICD-10-CM Codes›E00–E89›E20-E35›E23

ICD-10-CM E23.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E23.3 is a billable ICD-10-CM diagnosis code for hypothalamic dysfunction, not elsewhere classified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 643 through 645. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pituitary disorders.

Code Identity

ICD-10-CM Code
E23.3
Billable Status
Yes — Valid for Submission
Code Describes
Hypothalamic dysfunction, not elsewhere classified
Short Description
Hypothalamic dysfunction, not elsewhere classified
Same as the full description in the CMS dataset.
Parent Code
E23
Hypofunction and other disorders of the pituitary gland

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE20-E35Disorders of other endocrine glands
CategoryE23Hypofunction and other disorders of the pituitary gland
This CodeE23.3Hypothalamic dysfunction, not elsewhere classified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Absent osmoregulation
  • Adipsia
  • Amenorrhea due to hypothalamic disorder
  • Amenorrhea due to pituitary dysfunction
  • Central alveolar hypoventilation syndrome
  • Chronic hypernatremia
  • Defective osmoregulation
  • Endocrine axis dysfunction
  • Endocrine menstrual disturbance
  • Exercise induced hypothalamic insufficiency
  • Genetic syndromic childhood obesity
  • Hypernatremia
  • Hypernatremic dehydration
  • Hypoplasia of hypothalamus
  • Hypothalamic adipsic hypernatremia syndrome
  • Hypothalamic amenorrhea
  • Hypothalamic disorder of appetite
  • Hypothalamic overactivity
  • Hypothalamic syndrome
  • Hypothalamic-pituitary-gonadal axis dysfunction
  • Late-onset central hypoventilation co-occurrent and due to hypothalamic dysfunction
  • Loss of hypothalamic inhibition
  • Osmoregulation defect - absent thirst
  • Primary hypothalamic insufficiency
  • Rapid-onset childhood obesity, hypothalamic dysfunction, hypoventilation, autonomic dysregulation syndrome
  • Secondary hypothalamic insufficiency

Tabular List NotesGuidance

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

Type 1 Excludes

  • Prader-Willi syndrome Q87.11
  • Russell-Silver syndrome Q87.19

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.

    • Disorder(of)
      • neurohypophysis NEC
    • Dysfunction
      • hypothalamic NEC
    • Dysfunction
      • pituitary (gland)
    • Dyspituitarism
    • Overactive
      • hypothalamus
    • Renon-Delille syndrome

Clinical ClassificationClinical

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

CCSR END013
Pituitary disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Hypernatremia

    excessive amount of sodium in the blood. (dorland, 27th ed)

  • Grade 1 Hypernatremia, CTCAE|Grade 1 Hypernatremia

    >uln - 150 mmol/l

  • Grade 2 Hypernatremia, CTCAE|Grade 2 Hypernatremia

    >150 - 155 mmol/l; intervention initiated

  • Grade 3 Hypernatremia, CTCAE|Grade 3 Hypernatremia

    >155 - 160 mmol/l; hospitalization indicated

  • Secondary Amenorrhea

    the cessation of menstruation for six months or more in a female that is not pregnant, breastfeeding or menopausal.

  • Hypernatremic Dehydration

    dehydration resulting from abnormally high levels of sodium in the blood. infants and individuals that are intubated are at highest risk.

  • Grade 1 Hypernatremia, CTCAE|Grade 1 Hypernatremia

    >uln-150 mmol/l

  • Grade 2 Hypernatremia, CTCAE|Grade 2 Hypernatremia

    >150-155 mmol/l; intervention initiated

  • Grade 3 Hypernatremia, CTCAE|Grade 3 Hypernatremia

    >155-160 mmol/l; hospitalization indicated

  • Grade 4 Hypernatremia, CTCAE|Grade 4 Hypernatremia

    >160 mmol/l; life-threatening consequences

  • Grade 5 Hypernatremia, CTCAE|Grade 5 Hypernatremia

    death

  • Hypernatremia

    higher than normal levels of sodium in the circulating blood.

  • Hypernatremia, CTCAE|Hypernatremia|Hypernatremia

    a disorder characterized by laboratory test results that indicate an elevation in the concentration of sodium in the blood.

Patient EducationClinical

Pituitary Disorders

Your pituitary gland is a pea-sized gland at the base of your brain. The pituitary is the "master control gland" - it makes hormones that affect growth and the functions of other glands in the body.

Read the full article at MedlinePlus

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

Convert E23.3 to ICD-9-CMHistory

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

ICD-9-CM
253.9 Pituitary disorder 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 E23.3Overview

Is E23.3 (Hypofunction and other disorders of the pituitary gland) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report hypothalamic dysfunction, not elsewhere classified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E23.3 group to?

When hypothalamic dysfunction, not elsewhere classified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 643, 644, 645, with relative weights from 0.7683 to 1.6461 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E23.3?

Under the General Equivalence Mappings, hypothalamic dysfunction, not elsewhere classified converts to ICD-9-CM 253.9 (pituitary disorder NOS). 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.