2026 ICD-10-CM Diagnosis Code I27.23Pulmonary hypertension due to lung diseases and hypoxia

ICD-10-CM Codes›I00–I99›I26-I28›I27

ICD-10-CM I27.23
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I27.23 is a billable ICD-10-CM diagnosis code for pulmonary hypertension due to lung diseases and hypoxia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pulmonary heart disease.

This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such hypertension.

Code Identity

ICD-10-CM Code
I27.23
Billable Status
Yes — Valid for Submission
Code Describes
Pulmonary hypertension due to lung diseases and hypoxia
Short Description
Pulmonary hypertension due to lung diseases and hypoxia
Same as the full description in the CMS dataset.
Parent Code
I27.2
Other secondary pulmonary hypertension

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI26-I28Pulmonary heart disease and diseases of pulmonary circulation
CategoryI27Other pulmonary heart diseases
This CodeI27.23Pulmonary hypertension due to lung diseases and hypoxia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Lymphangiomyomatosis of connective tissue
  • Pulmonary hypertension associated with chronic underventilation
  • Pulmonary hypertension due to chronic obstructive pulmonary disease
  • Pulmonary hypertension due to developmental abnormality of the lung
  • Pulmonary hypertension due to interstitial lung disease
  • Pulmonary hypertension due to lung disease and/or hypoxia
  • Pulmonary hypertension due to pulmonary disease with mixed restrictive and obstructive pattern
  • Pulmonary hypertension in lymphangioleiomyomatosis
  • Pulmonary hypertension in systemic disorder
  • Pulmonary lymphangioleiomyomatosis

Tabular List NotesGuidance

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

Inclusion Terms

  • Group 3 pulmonary hypertension

Code Also

  • associated lung disease, if known, such as:
  • bronchiectasis J47
  • cystic fibrosis with pulmonary manifestations E84.0
  • interstitial lung disease J84
  • pleural effusion J90
  • sleep apnea G47.3

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)
      • pulmonary
        • due to
          • lung diseases and hypoxia
    • Hypertension, hypertensive(accelerated) (benign) (essential) (idiopathic) (malignant) (systemic)
      • pulmonary
        • group 3

Clinical ClassificationClinical

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

CCSR CIR014
Pulmonary heart disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Pulmonary Hypertension

Pulmonary hypertension, sometimes called PH, is a serious condition that affects the blood vessels in the lungs. It develops when the blood pressure in your lungs is higher than normal.

The full article covers:

  • What is pulmonary hypertension?
  • What causes pulmonary hypertension?
  • Who is more likely to develop pulmonary hypertension?
  • What are the symptoms of pulmonary hypertension?
  • What other problems can pulmonary hypertension cause?
  • How is pulmonary hypertension diagnosed?
  • What are the treatments for pulmonary hypertension?

Read the full article at MedlinePlus

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

Convert I27.23 to ICD-9-CMHistory

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

ICD-9-CM
416.8 Chr pulmon heart dis NEC
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement I27.23 replaces the following previously assigned code(s):

  • I27.2 - Other secondary pulmonary hypertension
FY 2018AddedAdded to the ICD-10-CM code setEffective October 1, 2017.
FY 2019–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About I27.23Overview

Is I27.23 (Other secondary pulmonary hypertension) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report pulmonary hypertension due to lung diseases and hypoxia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I27.23 group to?

When pulmonary hypertension due to lung diseases and hypoxia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I27.23?

Under the General Equivalence Mappings, pulmonary hypertension due to lung diseases and hypoxia converts to ICD-9-CM 416.8 (chr pulmon heart dis 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.