2024 ICD-10-CM Diagnosis Code I15.9

Secondary hypertension, unspecified

ICD-10-CM Code:
I15.9
ICD-10 Code for:
Secondary hypertension, unspecified
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Chronic
Code Navigator:

Code Classification

  • Diseases of the circulatory system
    (I00–I99)
    • Hypertensive diseases
      (I10-I1A)
      • Secondary hypertension
        (I15)

I15.9 is a billable diagnosis code used to specify a medical diagnosis of secondary hypertension, unspecified. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

Unspecified diagnosis codes like I15.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

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

  • Diastolic hypertension
  • Hypertensive crisis
  • Hypertensive emergency
  • Malignant hypertension
  • Malignant secondary hypertension
  • Paroxysmal hypertension
  • Perioperative hypertension
  • Pre-existing secondary hypertension complicating pregnancy, childbirth and puerperium
  • Secondary diastolic hypertension
  • Secondary hypertension

Clinical Classification

Clinical Information

  • Paroxysmal Hypertension

    hypertension that presents intermittently.
  • Diastolic Hypertension

    hypertension characterized diastolic blood pressure greater than 90 mmhg on two occasions.
  • Malignant Hypertension

    severe hypertension that is characterized by rapid onset of extremely high blood pressure.

Replaced Code

This code was replaced in the 2024 ICD-10-CM code set with the code(s) listed below. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2023. This code was replaced for the FY 2024 (October 1, 2023 - September 30, 2024).


  • I1A.0 - Resistant hypertension

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Convert I15.9 to ICD-9-CM

  • ICD-9-CM Code: 405.99 - Second hypertension NEC
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education


High Blood Pressure

What is 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. This is called diastolic pressure.

Your blood pressure reading uses these two numbers. Usually the systolic number comes before or above the diastolic number. For example, 120/80 means a systolic of 120 and a diastolic of 80.

How is high blood pressure diagnosed?

High blood pressure usually has no symptoms. So the only way to find out if you have it is to get regular blood pressure checks from your health care provider. Your provider will use a gauge, a stethoscope or electronic sensor, and a blood pressure cuff. He or she will take two or more readings at separate appointments before making a diagnosis.

Blood Pressure Category Systolic Blood Pressure Diastolic Blood Pressure
Normal Less than 120 and Less than 80
High Blood Pressure (no other heart risk factors) 140 or higher or 90 or higher
High Blood Pressure (with other heart risk factors, according to some providers) 130 or higher or 80 or higher
Dangerously high blood pressure - seek medical care right away 180 or higher and 120 or higher

For children and teens, the health care provider compares the blood pressure reading to what is normal for other kids who are the same age, height, and sex.

What are the different types of high blood pressure?

There are two main types of high blood pressure: primary and secondary high blood pressure.:

  • Primary, or essential, high blood pressure is the most common type of high blood pressure. For most people who get this kind of blood pressure, it develops over time as you get older.
  • Secondary high blood pressure is caused by another medical condition or use of certain medicines. It usually gets better after you treat that condition or stop taking the medicines that are causing it.

Why do I need to worry about high blood pressure?

When your blood pressure stays high over time, it causes the heart to pump harder and work overtime, possibly leading to serious health problems such as heart attack, stroke, heart failure, and kidney failure.

What are the treatments for high blood pressure?

Treatments for high blood pressure include heart-healthy lifestyle changes and medicines.

You will work with your provider to come up with a treatment plan. It may include only the lifestyle changes. These changes, such as heart-healthy eating and exercise, can be very effective. But sometimes the changes do not control or lower your high blood pressure. Then you may need to take medicine. There are different types of blood pressure medicines. Some people need to take more than one type.

If your high blood pressure is caused by another medical condition or medicine, treating that condition or stopping the medicine may lower your blood pressure.

NIH: National Heart, Lung, and Blood Institute


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • 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
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

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.