2026 ICD-10-CM Diagnosis Code I15.8Other secondary hypertension

ICD-10-CM Codes›I00–I99›I10-I1A›I15

ICD-10-CM I15.8
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I15.8 is a billable ICD-10-CM diagnosis code for other secondary hypertension. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 304 through 305. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Hypertension with complications and secondary hypertension.

Code Identity

ICD-10-CM Code
I15.8
Billable Status
Yes — Valid for Submission
Code Describes
Other secondary hypertension
Short Description
Other secondary hypertension
Same as the full description in the CMS dataset.
Parent Code
I15
Secondary hypertension

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI10-I1AHypertensive diseases
CategoryI15Secondary hypertension
This CodeI15.8Other secondary hypertension

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Benign hypertension
  • Benign secondary hypertension
  • Exertional hypertension
  • Hypertension associated with transplantation
  • Hypertension due to aortic arch obstruction
  • Hypertension due to gain-of-function mutation in mineralocorticoid receptor
  • Hypertension induced by oral contraceptive pill
  • Hypertension secondary to drug
  • Hypertension secondary to kidney transplant
  • Hypertension secondary to renal disease in obstetric context
  • Intermittent hypertension
  • Labile hypertension due to being in a clinical environment
  • Multiple drug intolerant hypertension
  • Postoperative hypertension
  • Secondary hypertension due to congenital heart disorder

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.

    • Hypertension, hypertensive(accelerated) (benign) (essential) (idiopathic) (malignant) (systemic)
      • due to
        • specified disease NEC
    • Hypertension, hypertensive(accelerated) (benign) (essential) (idiopathic) (malignant) (systemic)
      • secondary NEC
        • specified NEC

Clinical ClassificationClinical

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

CCSR CIR008
Hypertension with complications and secondary hypertension
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Benign Secondary Hypertension

    mild to moderate high blood pressure that is caused by an underlying medical condition.

  • Postoperative Hypertension

    a transient increase in blood pressure following a surgical procedure.

Patient EducationClinical

High Blood Pressure

Blood pressure is the force of your blood pushing against the walls of your arteries. Each time your heart beats, it pumps blood into the arteries. Your blood pressure is highest when your heart beats, pumping the blood. This is called systolic pressure. When your heart is at rest, between beats, your blood pressure falls.

The full article covers:

  • What is blood pressure?
  • How is high blood pressure diagnosed?
  • What are the different types of high blood pressure?
  • Why do I need to worry about high blood pressure?
  • What are the treatments for high blood pressure?

Read the full article at MedlinePlus

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

Convert I15.8 to ICD-9-CMHistory

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

ICD-9-CM
405.09 Mal second hyperten NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
405.19 Benign second hypert NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
405.99 Second hypertension NEC
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 I15.8Overview

Is I15.8 (Secondary hypertension) a billable code?

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

What MS-DRG does I15.8 group to?

When other secondary hypertension is the principal diagnosis on an inpatient stay, it groups to MS-DRG 304, 305, with relative weights from 0.7551 to 1.1900 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I15.8?

Under the General Equivalence Mappings, other secondary hypertension converts to ICD-9-CM 405.09 (mal second hyperten NEC), 405.19 (benign second hypert NEC), and 405.99 (second hypertension NEC). 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.