What N18 covers · when clinicians use it
ICD-10 code N18 identifies Chronic kidney disease (CKD) in the U.S. ICD-10-CM clinical and billing record set. It sits within the Genitourinary System chapter (N00–N99), the section that groups related diagnoses so providers, payers, and public-health agencies report them consistently. Clinicians and medical coders apply N18 when an encounter's findings match the Chronic kidney disease (CKD) description, attaching it to the patient record so downstream insurance claims, payer audits, quality reporting, and epidemiological surveillance all reference the same standardized diagnosis. The ICD-10-CM is maintained by the Centers for Medicare & Medicaid Services and the CDC's National Center for Health Statistics, with an updated official code set released each U.S. fiscal year — always verify N18 against the current CMS/CDC release and your payer's documentation guidance before final use. This page summarizes documentation context for N18 and is a coding reference, not clinical, diagnostic, or billing advice.
N18 refers to Chronic kidney disease (CKD), covering both sudden and progressive loss of kidney function, ranging from reversible acute conditions to permanent chronic kidney disease requiring lifelong management or renal replacement therapy.
Symptoms
- Decreased urine output – Hallmark of acute kidney failure (N17)
- Swelling in legs, ankles, or face – Due to fluid retention in CKD (N18)
- Fatigue and weakness – Resulting from toxin buildup in blood
- Shortness of breath – Due to fluid overload
- Confusion or seizures – Severe complication of kidney failure
Diagnosis
Diagnosis of Chronic kidney disease (CKD) includes blood tests (serum creatinine, BUN, electrolytes), estimated glomerular filtration rate (eGFR) measurement, urinalysis, imaging (renal ultrasound or CT), and sometimes kidney biopsy to determine the underlying cause.
ICD10 Code Usage
ICD10 code N18 is critical for documentation by nephrologists, intensivists, hospitalists, and internists to manage acute kidney injuries, monitor progression of chronic kidney disease stages, and appropriately plan dialysis or transplant interventions.
Related Codes
FAQs
Q1: What is ICD10 code N18?
A: It refers to Chronic kidney disease (CKD), encompassing the spectrum of kidney failure from sudden-onset acute injuries to long-term progressive chronic disease.
Q2: How is acute kidney failure (N17) different from CKD (N18)?
A: Acute kidney failure develops rapidly and may be reversible with prompt treatment, while CKD progresses slowly and often leads to permanent renal damage.
Q3: How is unspecified kidney failure (N19) used?
A: N19 is used when clinical data confirms kidney failure but the exact type (acute vs chronic) is not clearly documented or distinguishable at the time.
Q4: What are common causes of kidney failure?
A: Causes include diabetes, hypertension, sepsis, dehydration, toxins, autoimmune diseases, and urinary obstructions.
Q5: How is kidney failure managed?
A: Management includes addressing underlying causes, fluid and electrolyte balance, dialysis initiation when indicated, and preparation for kidney transplantation in end-stage cases.
Conclusion
ICD10 code N18 supports timely recognition, classification, and management of Chronic kidney disease (CKD), promoting improved patient outcomes through early intervention, progression monitoring, and renal support therapies.