What N20 covers · when clinicians use it
ICD-10 code N20 identifies Calculus of kidney and ureter 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 N20 when an encounter's findings match the Calculus of kidney and ureter 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 N20 against the current CMS/CDC release and your payer's documentation guidance before final use. This page summarizes documentation context for N20 and is a coding reference, not clinical, diagnostic, or billing advice.
N20 refers to Calculus of kidney and ureter, describing various forms of urinary tract stone disease that cause obstruction, severe pain (renal colic), and potential kidney damage if not promptly treated.
Symptoms
- Severe flank or abdominal pain – Hallmark of renal colic (N20, N23)
- Hematuria (blood in urine) – Due to stone irritation of urinary tract walls
- Frequent or painful urination – Especially in lower urinary tract stones (N21)
- Nausea and vomiting – Common with acute obstruction
- Urinary urgency – Particularly when bladder stones are involved
Diagnosis
Diagnosis of Calculus of kidney and ureter relies on clinical presentation, urinalysis (for blood or crystals), non-contrast CT scans of the abdomen/pelvis (gold standard), renal ultrasound, and plain abdominal X-rays in certain cases.
ICD10 Code Usage
ICD10 code N20 is used by urologists, nephrologists, emergency medicine physicians, and internists to document urinary stone disease, guide treatment such as lithotripsy, ureteroscopy, or surgery, and monitor recurrence risk.
Related Codes
- N21 – Calculus of lower urinary tract
- N22 – Calculus of urinary tract in diseases classified elsewhere
- N23 – Unspecified renal colic
FAQs
Q1: What is ICD10 code N20?
A: It refers to Calculus of kidney and ureter, covering kidney, ureter, bladder, and unspecified urinary stones presenting with pain, hematuria, or urinary obstruction.
Q2: What is the difference between N20 and N21?
A: N20 refers to stones in the kidney or ureter, while N21 refers to stones located in the bladder or urethra (lower urinary tract).
Q3: What is N23 (unspecified renal colic)?
A: Used when a patient presents with classical renal colic symptoms but the specific stone location or cause is not yet confirmed through imaging.
Q4: What causes urinary tract calculi?
A: Causes include dehydration, dietary factors (high oxalate or protein intake), infections, metabolic disorders, and family history.
Q5: How are urinary stones treated?
A: Small stones often pass spontaneously; larger stones may require medications, shock wave lithotripsy, ureteroscopy, or surgical removal depending on size and location.
Conclusion
ICD10 code N20 ensures accurate diagnosis, documentation, and management of Calculus of kidney and ureter, enabling effective treatment to relieve symptoms, prevent complications, and reduce future stone formation risks.