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ICD Code for Hypertension

Learn the correct ICD‑10‑CM codes for hypertension, including essential, secondary, heart and kidney disease categories, and how to select the most specific…

By True Impact Health Editorial Team

Updated on October 10, 2026 6 min read

ICD Code for Hypertension
Table of Contents

    Key Takeaways

    • Accurate hypertension coding impacts patient care, reimbursement, and public health data.
    • Use the most specific ICD-10-CM code based on organ involvement and cause.
    • Review provider notes, labs, and imaging to confirm heart or kidney disease.
    • Regular training and encoder tools help maintain compliance with coding guidelines.

    Quick answer

    ICD‑10‑CM codes for hypertension are found in Chapter 11 under I10 (essential/primary hypertension) and I15 (secondary hypertension), with sub‑codes I11‑I13 for heart and kidney involvement. Choose the most specific code that matches the patient’s documented blood‑pressure level, organ damage and underlying cause.

    Introduction

    Hypertension, also known as high blood pressure, is one of the most common chronic conditions worldwide. Accurate coding of hypertension in medical records isn’t just an administrative task; it impacts patient care, reimbursement, quality reporting, and public health data. In this blog post, we’ll dive into the ICD-10-CM codes for hypertension, explain when to use each code, and share best practices for precise, compliant coding.

    What Is Hypertension?

    Before we get into codes, let’s briefly review what hypertension entails:

    • Definition: A sustained elevation of systolic blood pressure ≥ 130 mm Hg or diastolic ≥ 80 mm Hg (per ACC/AHA guidelines).
    • Prevalence: Affects roughly 1 in 3 adults in the U.S.
    • Risks: Stroke, heart attack, kidney disease, and more.

  1. Overview of ICD-10-CM

    The International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) is the standard coding system used in the United States. ICD-10-CM codes for hypertension are found in Chapter 11 (Diseases of the circulatory system), under category I10, I15.

  2. A clinician measures a patient’s blood pressure, illustrating the data used for hypertension coding
    A clinician measures a patient’s blood pressure, illustrating the data used for hypertension coding. (Photo by Marta Branco on Pexels)

    Main ICD-10-CM Codes for Hypertension

    Here’s a breakdown of the primary codes and their subcategories:

    I10 Essential (Primary) Hypertension

    • I10: Essential (primary) hypertension
    • Use when no specific organ damage is documented.

    I11 Hypertensive Heart Disease

    • I11.0: Hypertensive heart disease with heart failure
    • I11.9: Hypertensive heart disease without heart failure

    I12 Hypertensive Chronic Kidney Disease

    • I12.0: Hypertensive chronic kidney disease with stage 5 or end-stage renal disease
    • I12.9: Hypertensive chronic kidney disease with stage 1-4 or unspecified CKD
    Coder reviewing electronic health records to select the correct ICD‑10‑CM hypertension code
    Coder reviewing electronic health records to select the correct ICD‑10‑CM hypertension code. (Photo by Syirwan Ainu on Pexels)

    I13 Hypertensive Heart and Chronic Kidney Disease

    • I13.0: With heart failure and stage 1-4 or unspecified CKD
    • I13.1: With heart failure and stage 5 or end-stage renal disease
    • I13.2: Without heart failure, with stage 1-4 or unspecified CKD
    • I13.9: Without heart failure, with stage 5 or ESRD

    I15 Secondary Hypertension

    • I15.0: Renovascular hypertension
    • I15.1: Hypertension secondary to other endocrine disorders
    • I15.2: Hypertension secondary to kidney disease
    • I15.8: Other secondary hypertension
    • I15.9: Secondary hypertension, unspecified

    How to Choose the Right Code

    Accurate selection depends on thorough clinical documentation. Follow these steps:

  3. Review the provider’s notes for:

    , Blood pressure readings and trends

    , Evidence of organ involvement (heart, kidney)

    , Underlying causes (renal artery stenosis, endocrine issues)

  4. Identify comorbid conditions: Document hypertensive heart disease or CKD.

  5. Match to the highest-specificity code: Always use the most detailed code available (e.g., I13.0 over I11.0 + I12.9).

  6. Graphic showing heart and kidney, highlighting organ involvement that determines specific hypertension codes
    Graphic showing heart and kidney, highlighting organ involvement that determines specific hypertension codes. (Photo by https://kaboompics.com/ on Pexels)

    Best Practices and Tips for Coders

    • Cross-check lab results and imaging reports for kidney function or cardiac findings.
    • Consult the Tabular List and Official Guidelines for Coding and Reporting.
    • Use combination codes (I13.x) when both heart and kidney disease are present.
    • Update training annually to reflect guideline changes.
    • Leverage encoder software with built-in validation rules.

  7. Why Accurate Hypertension Coding Matters

    • Reimbursement: Payers require precise coding to justify treatment and resource utilization.
    • Quality Metrics: Hypertension control is a core quality measure (e.g., HEDIS).
    • Population Health: Reliable data on hypertension prevalence guides public health initiatives.
    • Legal and Compliance: Reduces auditing risk and ensures regulatory adherence.

    Frequently Asked Questions

    How often should hypertension ICD-10 codes be reviewed?

    Codes should be reviewed whenever new clinical information becomes available and at least annually during coder training to capture updates in guidelines.

    What is the difference between I10 and I15 hypertension codes?

    I10 refers to essential (primary) hypertension without a known secondary cause, while I15 covers secondary hypertension caused by conditions such as renal artery stenosis or endocrine disorders.

    Can a patient have both essential and secondary hypertension codes?

    Typically only the secondary cause (I15 series) is coded when an underlying condition is documented, as it supersedes essential hypertension.

    How does accurate coding affect quality metrics like HEDIS?

    Precise codes ensure hypertension control rates are reported correctly, influencing HEDIS scores, reimbursement incentives, and population health initiatives.

    Conclusion

    Hypertension is a pervasive condition with significant clinical and financial implications. By mastering ICD-10-CM codes I10, I15, medical coders and healthcare providers can ensure accurate documentation, appropriate reimbursement, and high-quality patient care. Remember: the more specific the code, the better we can track disease burden, tailor treatments, and support public health goals.

    Ready to sharpen your coding skills? Keep your coding manuals close, stay current with official updates, and always aim for the highest level of specificity in your hypertension coding.

    For more information, see the Cleveland Clinic.

    When to see a doctor

    • Severe headache, vision changes, or confusion
    • Chest pain or shortness of breath
    • Sudden numbness or weakness on one side of the body
    • Blood pressure reading above 180/120 mm Hg
    • Rapid swelling of the legs or ankles
    • Call emergency services if any of these occur

    If symptoms are severe or come on suddenly, call your local emergency number.

    Frequently asked questions

    What code should I use for a patient with hypertension and diabetes?

    Document each condition separately. Use the appropriate hypertension code (e.g., I10) and code diabetes according to its type and complications. Do not combine them into a single code.

    How do I code hypertension that is well‑controlled with medication?

    Code the hypertension based on the underlying diagnosis (I10 or I15 series) regardless of control status. Add a modifier or note about control if required by payer guidelines.

    When is it appropriate to use I13 (hypertensive heart and chronic kidney disease) instead of separate I11 and I12 codes?

    Use I13 when documentation shows both hypertensive heart disease and chronic kidney disease in the same encounter. It is a combination code that captures both organ systems in one line.

    Can I code secondary hypertension if the underlying cause is not yet identified?

    If the provider suspects a secondary cause but it is not specified, use I15.9 (secondary hypertension, unspecified). If no secondary cause is documented, code I10.

    Sources and further reading

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    Medically reviewed by

    Dr. Oluwabusola Stella Oke

    Medical graduate of Girne American University with a focus on patient-centred care, clinical assessment and preventive health.

    True Impact Health articles are written by our editorial team and based on reliable sources such as public health agencies, clinical guidelines and peer-reviewed research. This article has been checked by a doctor on our review panel. Read our editorial process.

    This content is for general information and is not a substitute for professional medical advice, diagnosis or treatment.

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