2022 ICD-10-CM Code I27.21

Secondary pulmonary arterial hypertension

Version 2021

Valid for Submission

ICD-10:I27.21
Short Description:Secondary pulmonary arterial hypertension
Long Description:Secondary pulmonary arterial hypertension

Code Classification

  • Diseases of the circulatory system (I00–I99)
    • Pulmonary heart disease and diseases of pulmonary circulation (I26-I28)
      • Other pulmonary heart diseases (I27)

I27.21 is a billable diagnosis code used to specify a medical diagnosis of secondary pulmonary arterial hypertension. The code I27.21 is valid during the fiscal year 2022 from October 01, 2021 through September 30, 2022 for the submission of HIPAA-covered transactions.

The ICD-10-CM code I27.21 might also be used to specify conditions or terms like associated pulmonary arterial hypertension, associated pulmonary arterial hypertension, pulmonary arterial hypertension associated with chronic hemolytic anemia, pulmonary arterial hypertension associated with congenital heart disease, pulmonary arterial hypertension associated with congenital systemic-to-pulmonary shunt , pulmonary arterial hypertension associated with connective tissue disease, etc.

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code I27.21:


Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.

Code Also

Code Also
A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code I27.21 are found in the index:

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Replacement Code

I2721 replaces the following previously assigned ICD-10 code(s):

Convert I27.21 to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code I27.21 its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

Information for Patients


Pulmonary Hypertension

Pulmonary hypertension (PH) is high blood pressure in the arteries to your lungs. It is a serious condition. If you have it, the blood vessels that carry blood from your heart to your lungs become hard and narrow. Your heart has to work harder to pump the blood through. Over time, your heart weakens and cannot do its job and you can develop heart failure.

Symptoms of PH include

As PH worsens, you may find it hard to do any physical activities.

There are two main kinds of PH. One runs in families or appears for no known reason. The other kind is related to another condition, usually heart or lung disease.

There is no cure for PH. Treatments can control symptoms. They involve treating the heart or lung disease, medicines, oxygen, and sometimes lung transplantation.

NIH: National Heart, Lung, and Blood Institute


[Learn More in MedlinePlus]

Pulmonary arterial hypertension

Pulmonary arterial hypertension is a progressive disorder characterized by abnormally high blood pressure (hypertension) in the pulmonary artery, the blood vessel that carries blood from the heart to the lungs. Pulmonary arterial hypertension is one form of a broader condition known as pulmonary hypertension. Pulmonary hypertension occurs when most of the very small arteries throughout the lungs narrow in diameter, which increases the resistance to blood flow through the lungs. To overcome the increased resistance, blood pressure increases in the pulmonary artery and in the right ventricle of the heart, which is the chamber that pumps blood into the pulmonary artery. Ultimately, the increased blood pressure can damage the right ventricle of the heart.

Signs and symptoms of pulmonary arterial hypertension occur when increased blood pressure cannot fully overcome the elevated resistance. As a result, the flow of oxygenated blood from the lungs to the rest of the body is insufficient. Shortness of breath (dyspnea) during exertion and fainting spells are the most common symptoms of pulmonary arterial hypertension. People with this disorder may experience additional symptoms, particularly as the condition worsens. Other symptoms include dizziness, swelling (edema) of the ankles or legs, chest pain, and a rapid heart rate.


[Learn More in MedlinePlus]

Code History

  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018