2026 ICD-10-CM Diagnosis Code N18.4

Chronic kidney disease, stage 4 (severe)

ICD-10-CM Code:
N18.4
ICD-10 Code for:
Chronic kidney disease, stage 4 (severe)
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Chronic
Code Navigator:

N18.4 is a billable diagnosis code used to specify a medical diagnosis of chronic kidney disease, stage 4 (severe). The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

Code Classification

  • Diseases of the genitourinary system
    N00–N99
    • Acute kidney failure and chronic kidney disease
      N17-N19
      • Chronic kidney disease (N18)
        CKD

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • Anemia in chronic kidney disease
  • Anemia in chronic kidney disease stage 4
  • Benign hypertensive heart disease
  • Benign hypertensive heart disease and chronic renal disease stage 4
  • Chronic kidney disease due to benign hypertension
  • Chronic kidney disease stage 4
  • Chronic kidney disease stage 4 due to benign hypertension
  • Chronic kidney disease stage 4 due to drug induced diabetes mellitus
  • Chronic kidney disease stage 4 due to hypertension
  • Chronic kidney disease stage 4 due to hypertension
  • Chronic kidney disease stage 4 due to hypertension
  • Chronic kidney disease stage 4 due to hypertension
  • Chronic kidney disease stage 4 due to type 1 diabetes mellitus
  • Chronic kidney disease stage 4 due to type 1 diabetes mellitus
  • Chronic kidney disease stage 4 due to type 2 diabetes mellitus
  • Chronic kidney disease stage 4 due to type 2 diabetes mellitus
  • Disorder of kidney due to drug induced diabetes mellitus
  • Hypertension in chronic kidney disease due to type 1 diabetes mellitus
  • Hypertension in chronic kidney disease due to type 2 diabetes mellitus
  • Hypertension in chronic kidney disease stage 4 due to type 1 diabetes mellitus
  • Hypertension in chronic kidney disease stage 4 due to type 2 diabetes mellitus
  • Hypertensive heart AND chronic kidney disease stage 4
  • Malignant hypertensive chronic kidney disease
  • Malignant hypertensive chronic kidney disease stage 4
  • Malignant hypertensive heart disease
  • Malignant hypertensive heart disease and chronic renal disease stage 4
  • Malignant hypertensive renal disease
  • Nephropathy due to secondary diabetes mellitus

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Chronic kidney disease

CCSR Code: GEN003

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

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).

Index of External Cause of Injuries

References found for this diagnosis code in the External Cause of Injuries Index:

    • Disease, diseased
      • kidney (functional) (pelvis)
        • chronic
          • stage 4 (severe)

Convert N18.4 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Chr kidney dis stage IV

ICD-9-CM: 585.4

This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes.

Patient Education


Chronic Kidney Disease

You have two kidneys, each about the size of your fist. Their main job is to filter your blood. They remove wastes and extra water, which become urine. They also keep the body's chemicals balanced, help control blood pressure, and make hormones.

Chronic kidney disease (CKD) means that your kidneys are damaged and can't filter blood as they should. This damage can cause wastes to build up in your body. It can also cause other problems that can harm your health. Diabetes and high blood pressure are the most common causes of CKD.

The kidney damage occurs slowly over many years. Many people don't have any symptoms until their kidney disease is very advanced. Blood and urine tests are the only way to know if you have kidney disease.

Treatments cannot cure kidney disease, but they may slow kidney disease. They include medicines to lower blood pressure, control blood sugar, and lower cholesterol. CKD may still get worse over time. Sometimes it can lead to kidney failure. If your kidneys fail, you will need dialysis or a kidney transplantation.

You can take steps to keep your kidneys healthier longer:

  • Choose foods with less salt (sodium)
  • Control your blood pressure; your health care provider can tell you what your blood pressure should be
  • Keep your blood sugar in the target range, if you have diabetes
  • Limit the amount of alcohol you drink
  • Choose foods that are healthy for your heart: fruits, vegetables, whole grains, and low-fat dairy foods
  • Lose weight if you are overweight
  • Be physically active
  • Don't smoke

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


[Learn More in MedlinePlus]

Chronic Kidney Disease (CKD)

Overview of chronic kidney disease (CKD), including definition, causes, tests and diagnosis, managing CKD, eating right with CKD, and preventing CKD.
[Learn More in MedlinePlus]

Code History

  • FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
  • FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
  • 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.