2027 ICD-10-CM Diagnosis Code E23.1Drug-induced hypopituitarism

ICD-10-CM Codes›E00–E89›E20-E35›E23

ICD-10-CM E23.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

E23.1 is a billable ICD-10-CM diagnosis code for drug-induced hypopituitarism. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 643 through 645. Coders also document this condition as effects of immunotherapy. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Drug induced or toxic related condition and Pituitary disorders.

E23.1 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 23 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 23, ESRD (V21) category 23, ESRD (V24) category 23, and RxHCC Part D (V08) category 43 for payment year 2027.

Code Identity

ICD-10-CM Code
E23.1
Billable Status
Yes — Valid for Submission
Code Describes
Drug-induced hypopituitarism
Short Description
Drug-induced hypopituitarism
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 CodeE23.1Drug-induced hypopituitarism

Medicare Risk Adjustment (HCC)Billing

E23.1 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 23
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 23 · ESRD (V21): HCC 23 · ESRD (V24): HCC 23
ESRD V21 weights: 0.013 dialysis, 0.234–0.359 functioning graft · ESRD V24 weights: 0.036 dialysis, 0.217–0.390 functioning graft
Part D (RxHCC)
RxHCC 43 — Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Effects of immunotherapy
  • Hormone-induced hypopituitarism
  • Hypophysitis caused by drug
  • Hypopituitarism caused by drug
  • Hypopituitarism due to iron overload
  • Hypopituitarism following procedure
  • Iatrogenic hypopituitarism
  • Iatrogenic pituitary disorder
  • Immunotherapy induced hypophysitis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to E23.1: its own notes plus those printed at E23, block E20-E35, and Chapter 4. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From E23 Hypofunction and other disorders of the pituitary gland applies to 6 codes
  • the listed conditions whether the disorder is in the pituitary or the hypothalamus

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From E23 Hypofunction and other disorders of the pituitary gland applies to 6 codes
  • postprocedural hypopituitarism (E89.3)
  • short stature due to endocrine disorder (E34.3-)
From Block E20-E35 Disorders of other endocrine glands applies to 99 codes
From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • transitory endocrine and metabolic disorders specific to newborn (P70-P74)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

  • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Notes

General instructions on how these codes are used.

From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name E23.1, its category, or a range that includes it.

Code First 1

These codes say to code first a condition named in the note, and E23.1 is one of the conditions named.

  • G63 Polyneuropathy in diseases classified elsewhere
    endocrine disease, except diabetes (E00-E07, E15-E16, E20-E34) names E20-E34, which includes this code

Notes 1

These notes mention E23.1.

  • Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases
    All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere. names E16-E31, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR INJ030
Drug induced or toxic related condition
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR END013
Pituitary disorders
Default principal diagnosis: inpatient No · outpatient No

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 E23.1 to ICD-9-CMHistory

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

ICD-9-CM
253.7 Iatrogenic pituitary dis
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About E23.1Overview

What is the ICD-10 code for drug-induced hypopituitarism?

The ICD-10-CM code for drug-induced hypopituitarism is E23.1 (sometimes written as E231). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is E23.1 (Hypofunction and other disorders of the pituitary gland) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report drug-induced hypopituitarism on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does E23.1 group to?

When drug-induced hypopituitarism is the principal diagnosis on an inpatient stay, it groups to MS-DRG 644, 645, 643, with relative weights from 0.7461 to 1.6138 depending on complications. Higher weights mean higher Medicare reimbursement.

Can E23.1 be reported with E89.3?

Not as a rule. The Excludes1 note at E23, which applies to E23.1, lists "postprocedural hypopituitarism (E89.3)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does E23.1 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5). The additional code is reported after E23.1.

Does E23.1 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. E23.1 mapped to HCC 23 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 23 (Other Significant Endocrine and Metabolic Disorders), ESRD (V21) category 23 (Other Significant Endocrine and Metabolic Disorders), ESRD (V24) category 23 (Other Significant Endocrine and Metabolic Disorders), and RxHCC Part D (V08) category 43 (Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders).