Proteinuria ICD-10-CM Codes

Proteinuria ICD-10-CM Codes

Learn about the ICD-10 codes for proteinuria that you can use through this guide.

By Matt Olivares on Aug 8, 2025.

Fact Checked by Karina Jimenea.

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What ICD-10 codes are used for proteinuria?

Proteinuria is a medical condition characterized by excess protein in the urine. In the ICD-10 coding system, several codes are used to classify and document cases of proteinuria. 

Here are the commonly used proteinuria ICD-10 codes, along with their clinical descriptions:

  • N04.9 - Nephrotic syndrome with unspecified morphologic changes: Nephrotic syndrome is a kidney disorder that often results in severe proteinuria, typically with an albumin-to-creatinine ratio greater than 3.5. It can lead to edema, hypoalbuminemia, and hyperlipidemia.
  • N18.1 - Chronic kidney disease, stage 1: In this early stage of chronic kidney disease (CKD), proteinuria is one of the markers of kidney damage. The glomerular filtration rate (GFR) remains normal or only slightly reduced.
  • N18.2 - Chronic kidney disease, stage 2 (mild): CKD stage 2 indicates a mild reduction in kidney function with persistent proteinuria. The GFR is moderately reduced.
  • N18.3 - Chronic kidney disease, stage 3 (moderate): This stage signifies moderate CKD, where proteinuria often coexists with declining kidney function (GFR). It may require more intensive monitoring and management. This code is no longer valid and billable. Please use any of the more specific versions: N18.30 (stage 3 unspecified), N18.31 (stage 3a), or N18.32 (stage 3b).
  • E11.21 - Type 2 diabetes mellitus with diabetic nephropathy: Diabetic nephropathy is a common complication of diabetes, characterized by proteinuria and kidney damage. Proper management is crucial to slow its progression.
  • Q87.81 - Alport syndrome: Alport syndrome is a genetic disorder affecting the kidneys and often resulting in proteinuria, hematuria, and hearing loss. Early diagnosis and management are crucial.
  • N05.9 - Unspecified nephritic syndrome with unspecified morphologic changes: Nephritic syndrome is characterized by hematuria, proteinuria, and hypertension. This code is used when a specific cause is not identified.
  • R80.9 - Proteinuria, unspecified: When the underlying cause of proteinuria is not clear, or the condition is not otherwise specified, this code is used to document the presence of proteinuria in the patient.

These ICD-10 codes and clinical descriptions help healthcare professionals accurately document and track cases of proteinuria, allowing for appropriate diagnosis and treatment of the underlying conditions. Proper coding is essential for effective patient care and medical research.

Which proteinuria ICD codes are billable?

All of the aforementioned proteinuria ICD-10-CM codes are valid and billable, except for N18.3.

Billing in healthcare is complex and requires accurate coding, clinical documentation, and compliance with regulations. Reimbursement and billing rules vary by system and insurance plans. Consult a medical coder or billing expert for up-to-date information on billable codes.

Clinical information

  • Proteinuria is characterized by excess protein in the urine, typically not detectable in a healthy individual's urine.
  • Proteinuria can be categorized as either transient or persistent. Transient proteinuria can result from factors like fever, vigorous exercise, or emotional stress and usually resolves independently. Persistent proteinuria may indicate an underlying medical condition.
  • Proteinuria is diagnosed through a urine test, typically a urine dipstick or a 24-hour urine collection. The results are often reported as the amount of protein excreted per day.
  • Proteinuria can indicate kidney disease, diabetes, hypertension, autoimmune disorders, or other systemic conditions. The degree of proteinuria may correlate with the severity of the underlying condition.
  • The presence of different types of proteins in the urine, mainly albumin (albuminuria), is a common indicator of kidney damage. Microalbuminuria, a specific form of albuminuria, is essential in the early detection of kidney disease, especially in diabetes.
  • Underlying causes of proteinuria can include glomerular diseases, nephrotic syndrome, diabetic nephropathy, hypertension, and infections, among others.
  • Treatment of proteinuria aims to address the underlying cause, manage associated conditions (e.g., diabetes or hypertension), and protect kidney function. It may involve lifestyle modifications, medications, and regular monitoring.
  • If left untreated, proteinuria can progress to more severe kidney damage and contribute to chronic kidney disease (CKD) or end-stage renal disease (ESRD).
  • Regular follow-up and monitoring are crucial for patients with proteinuria to assess the effectiveness of treatment and to detect any deterioration in kidney function.
  • The prognosis for individuals with proteinuria depends on the underlying cause and the effectiveness of treatment. Early detection and management can improve outcomes.

Patients with proteinuria often benefit from a multidisciplinary care team involving nephrologists, primary care physicians, dietitians, and other.

Synonyms include

  • Albuminuria
  • Protein in the urine
  • Urinary protein
  • Protein excretion
  • Protein leakage
  • Abnormal findings showing proteinuria
  • Abnormal clinical findings showing proteinuria
  • Proteinuria due to low blood pressure
  • Proteinuria with specified morphological lesion

Popular search terms for proteinuria ICD-10-CM codes

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  • Proteinuria diagnosis codes
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Commonly asked questions

Use a proteinuria ICD code when documenting cases of proteinuria in medical records, mainly when associated with an underlying condition or as part of a diagnosis.

Most of them are billable as long as proper documentation and guidelines are followed.

Treatment depends on the underlying cause. It may include managing conditions like diabetes or hypertension, lifestyle modifications, medications, or addressing kidney disease if present.

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