2026 ICD-10-CM Diagnosis Code I27.0Primary pulmonary hypertension

ICD-10-CM Codes›I00–I99›I26-I28›I27

ICD-10-CM I27.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I27.0 is a billable ICD-10-CM diagnosis code for primary pulmonary hypertension. 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
I27.0
Billable Status
Yes — Valid for Submission
Code Describes
Primary pulmonary hypertension
Short Description
Primary pulmonary hypertension
Same as the full description in the CMS dataset.
Parent Code
I27
Other pulmonary heart diseases

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI26-I28Pulmonary heart disease and diseases of pulmonary circulation
CategoryI27Other pulmonary heart diseases
This CodeI27.0Primary pulmonary hypertension

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Ayerza's syndrome
  • Cor pulmonale
  • Familial primary pulmonary hypertension
  • Finding of pulmonary arterial pressure
  • Heritable pulmonary arterial hypertension
  • Heritable pulmonary arterial hypertension due to ALK1 or endoglin mutation
  • Heritable pulmonary arterial hypertension due to BMPR2 mutation
  • Idiopathic pulmonary arterial hypertension
  • Idiopathic pulmonary arteriosclerosis
  • Pulmonary arterial pressure above reference range
  • Right ventricular failure due to pulmonary vascular disease
  • Sporadic primary pulmonary hypertension

Tabular List NotesGuidance

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

Inclusion Terms

  • Heritable pulmonary arterial hypertension
  • Idiopathic pulmonary arterial hypertension
  • Primary group 1 pulmonary hypertension
  • Primary pulmonary arterial hypertension

Type 1 Excludes

  • persistent pulmonary hypertension of newborn P29.30
  • pulmonary hypertension NOS I27.20
  • secondary pulmonary arterial hypertension I27.21
  • secondary pulmonary hypertension I27.29

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.

    • Arrillaga-Ayerza syndrome(pulmonary sclerosis with pulmonary hypertension)
    • Arteriosclerosis, arteriosclerotic(diffuse) (obliterans) (of) (senile) (with calcification)
      • pulmonary (idiopathic)
    • Ayerza's disease or syndrome(pulmonary artery sclerosis with pulmonary hypertension)
    • Cardiopathia nigra
    • Disease, diseased
      • Ayerza's (pulmonary artery sclerosis with pulmonary hypertension)
    • Disease, diseased
      • heart (organic)
        • black
    • Disease, diseased
      • pulmonary
        • hypertensive (vascular)
          • primary (idiopathic)
    • Hypertension, hypertensive(accelerated) (benign) (essential) (idiopathic) (malignant) (systemic)
      • lesser circulation
    • Hypertension, hypertensive(accelerated) (benign) (essential) (idiopathic) (malignant) (systemic)
      • pulmonary
        • primary (idiopathic)
    • Sclerosis, sclerotic
      • pulmonary
        • artery
    • Syndrome
      • Arrillaga-Ayerza
    • Syndrome
      • Ayerza (-Arrillaga)
    • Syndrome
      • cardiacos negros
    • Syndrome
      • pulmonary
        • arteriosclerosis

Clinical ClassificationClinical

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

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

Clinical InformationClinical

  • Familial Primary Pulmonary Hypertension

    familial or idiopathic hypertension in the pulmonary circulation which is not secondary to other disease.

  • Pulmonary Circulation

    the circulation of the blood through the lungs.

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 I27.0 to ICD-9-CMHistory

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

ICD-9-CM
416.0 Prim pulm hypertension
Exact Match The mapping is direct, with no qualifiers.

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 I27.0Overview

Is I27.0 (Other pulmonary heart diseases) a billable code?

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

What MS-DRG does I27.0 group to?

When primary pulmonary hypertension 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 I27.0?

Under the General Equivalence Mappings, primary pulmonary hypertension converts to ICD-9-CM 416.0 (prim pulm hypertension). The mapping is a direct match.

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.