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  6. 2025 ICD-10-CM Code N00.9

2025 ICD-10-CM Diagnosis Code N00.9

Acute nephritic syndrome with unspecified morphologic changes

ICD-10-CM Code:
N00.9
ICD-10 Code for:
Acute nephritic syndrome with unsp morphologic changes
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

N00.9 is a billable diagnosis code used to specify a medical diagnosis of acute nephritic syndrome with unspecified morphologic changes. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2024 through September 30, 2025.

Unspecified diagnosis codes like N00.9 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.

Code Classification

  • Diseases of the genitourinary system
    N00–N99
    • Glomerular diseases
      N00-N08
      • Acute nephritic syndrome
        N00

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.

  • Acute diffuse nephritis
  • Acute exudative glomerulonephritis
  • Acute exudative nephritis
  • Acute focal nephritis
  • Acute glomerulonephritis
  • Acute glomerulonephritis associated with another disorder
  • Acute glomerulonephritis associated with another disorder
  • Acute nephritis
  • Acute nephritis due to another disorder
  • Acute nephritis due to another disorder
  • Acute post-streptococcal glomerulonephritis
  • Acute radiation nephritis
  • Anaphylactoid glomerulonephritis
  • Exudative glomerulonephritis
  • Exudative nephritis
  • Exudative nephritis
  • Glomerular disease due to infectious disease
  • Post-infectious glomerulonephritis
  • Radiation nephritis

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.

Nephritis; nephrosis; renal sclerosis

CCSR Code: GEN001

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.

Clinical Information

  • Exudative Glomerulonephritis

    inflammation of the glomeruli with infiltration by polymorphonuclear leukocytes.

  • Acute Glomerulonephritis

    an acute inflammation of the glomeruli, generally secondary to infection or injury.

  • Subacute Glomerulonephritis

    a term that refers to glomerular damage resulting in hematuria, proteinuria, and azotemia. the histopathologic changes include rapidly progressive glomerulonephritis and membranoproliferative glomerulonephritis.

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 N00.9 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.

Acute nephritis NOS

ICD-9-CM: 580.9

Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.

View Conversion

Patient Education


Kidney Diseases

You have two kidneys, each about the size of your fist. They are near the middle of your back, just below the rib cage. Inside each kidney there are about a million tiny structures called nephrons. They filter your blood. They remove wastes and extra water, which become urine. The urine flows through tubes called ureters. It goes to your bladder, which stores the urine until you go to the bathroom.

Most kidney diseases attack the nephrons. This damage may leave kidneys unable to remove wastes. Causes can include genetic problems, injuries, or medicines. You have a higher risk of kidney disease if you have diabetes, high blood pressure, or a close family member with kidney disease. Chronic kidney disease damages the nephrons slowly over several years. Other kidney problems include:

  • Cancer
  • Cysts
  • Stones
  • Infections

Your doctor can do blood and urine tests to check if you have kidney disease. If your kidneys fail, you will need dialysis or a kidney transplant.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


[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] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.