2026 ICD-10-CM Diagnosis Code E26.09Other primary hyperaldosteronism

ICD-10-CM Codes›E00–E89›E20-E35›E26

ICD-10-CM E26.09
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E26.09 is a billable ICD-10-CM diagnosis code for other primary hyperaldosteronism. 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. Coders also document this condition as familial hyperaldosteronism. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified endocrine disorders.

Code Identity

ICD-10-CM Code
E26.09
Billable Status
Yes — Valid for Submission
Code Describes
Other primary hyperaldosteronism
Short Description
Other primary hyperaldosteronism
Same as the full description in the CMS dataset.
Parent Code
E26.0
Primary hyperaldosteronism

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE20-E35Disorders of other endocrine glands
CategoryE26Hyperaldosteronism
This CodeE26.09Other primary hyperaldosteronism

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Familial hyperaldosteronism
  • Familial hyperaldosteronism type 4
  • Hyperaldosteronism co-occurrent with hyperplasia of the adrenal cortex
  • Idiopathic hyperaldosteronism
  • Primary aldosteronism
  • Primary hyperaldosteronism due to aldosterone-secreting malignant neoplasm of adrenal gland
  • Primary hyperaldosteronism due to hyperplasia
  • Primary hyperaldosteronism, seizures, neurological abnormalities syndrome

Tabular List NotesGuidance

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

Inclusion Terms

  • Primary aldosteronism due to adrenal hyperplasia (bilateral)

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.

    • Aldosteronism
      • primary (due to (bilateral) adrenal hyperplasia)
    • Aldosteronism
      • primary NEC
    • Hyperaldosteronism
      • primary (due to (bilateral) adrenal hyperplasia)
    • Hyperaldosteronism
      • primary NEC

Clinical ClassificationClinical

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

CCSR END015
Other specified and unspecified endocrine disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Familial Hyperaldosteronism

    a heritable form of hyperaldosteronism.

  • Familial Hyperaldosteronism Type 1|CYP11B1/CYP11B2 Chimerism|Glucocorticoid Remediable Aldosteronism|Glucocorticoid Suppressible Hypertension|Glucocorticoid-responsive primary hyperaldosteronism

    familial hyperaldosteronism caused by a chimeric gene containing regions of cyp11b1 and cyp11b2. this condition is responsive to exogenous glucocorticoids.

  • Familial Hyperaldosteronism Type 2

    familial hyperaldosteronism unresponsive to glucocorticoid therapy. the molecular basis for this condition has not been fully elucidated.

  • Familial Hyperaldosteronism Type 3

    familial hyperaldosteronism caused by a mutation in the kcnj5 gene, which encodes the inwardly rectifying potassium channel. this condition, characterized by hypokalemia and severe hypertension, presents during early childhood, and is unresponsive to glucocorticoid therapy.

Patient EducationClinical

Adrenal Gland Disorders

Your adrenal glands are two small organs that sit on top of each kidney. The adrenal glands make different types of hormones you need to stay alive and healthy. Hormones are chemicals that travel in your bloodstream and control how different parts of your body work.

The full article covers:

  • What are adrenal glands?
  • What are adrenal gland disorders?
  • What causes adrenal gland disorders?
  • How are adrenal gland disorders diagnosed?
  • What are the treatments for adrenal gland disorders?

Read the full article at MedlinePlus

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

Convert E26.09 to ICD-9-CMHistory

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

ICD-9-CM
255.10 Hyperaldosteronism 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 E26.09Overview

Is E26.09 (Primary hyperaldosteronism) a billable code?

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

What MS-DRG does E26.09 group to?

When other primary hyperaldosteronism 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 E26.09?

Under the General Equivalence Mappings, other primary hyperaldosteronism converts to ICD-9-CM 255.10 (hyperaldosteronism 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.