2025 ICD-10-CM code N21.8
(Active) Effective Date: N/A Revision Date: N/A Deletion Date: N/A Urolithiasis - Calculus of lower urinary tract Diseases of the genitourinary system (N00-N99) Feed
Other lower urinary tract calculus; this code is used to classify urinary stones located in the bladder or urethra, excluding those specifically mentioned in other codes.
Modifiers may be applicable to procedures performed to manage the calculus; check the current CPT and HCPCS coding guidelines for specific modifier usage.
Medical necessity for coding N21.8 is established by the presence of symptoms (pain, urinary retention, hematuria) and confirmation of the stone through imaging or other diagnostic procedures.The need for intervention (e.g., lithotripsy, ureteroscopy) further supports medical necessity.
Urologist, nephrologist, or other physician managing urinary tract conditions.
In simple words: This code means you have a kidney stone or bladder stone in your lower urinary tract (bladder or urethra) that isn't specifically described by other, more precise codes.Kidney stones can cause pain and sometimes blood in your urine.
N21.8, "Other lower urinary tract calculus," in the ICD-10-CM classification system, denotes the presence of urinary calculi (stones) in the lower urinary tract.This includes stones in the bladder or urethra that do not meet the specific criteria for codes N21.0 (calculus in bladder) or N21.1 (calculus in urethra).The code encompasses a range of stone compositions and sizes, requiring further specification in clinical documentation to clarify the precise nature and location of the calculi.
Example 1: A 60-year-old male patient presents with severe flank pain radiating to the groin, hematuria, and dysuria.Imaging studies reveal a 5mm stone in the distal ureter. The physician documents this as N21.8 because the stone's exact location does not fit the criteria for N21.0 or N21.1., A 35-year-old female patient complains of urinary frequency, urgency, and suprapubic pain.Cystoscopy reveals a small stone in the bladder.The stone's composition is not immediately apparent, so the physician uses N21.8 until further lab results are available. , A 72-year-old male with a history of benign prostatic hyperplasia presents with acute urinary retention.A urethral stone is identified during catheterization. While the exact location of formation isn't known,N21.8 is used to reflect the stone in the urethra, needing additional documentation to specify cause or composition.
Detailed patient history, including symptoms (pain location, severity, character, frequency of urination, presence of hematuria); results of diagnostic imaging (X-ray, CT scan, ultrasound) to confirm the presence and location of the stone; laboratory results (urinalysis to assess for infection, blood, and stone composition) are all necessary for proper coding.
** Further documentation should specify the stone's size, composition (if known), and any associated complications (infection, obstruction). The location in the lower urinary tract should be clarified (bladder or urethra).If the stone is causing significant symptoms or obstruction, additional codes might be required to reflect those conditions.Always cross-reference with the most up-to-date guidelines and coding manuals.
- Payment Status: Active
- Modifier TC rule: Modifier TC may apply in specific circumstances related to the treatment of the stone, depending on the procedure and its location. Refer to CPT coding guidelines.
- Specialties:Urology, Nephrology
- Place of Service:Office, Hospital Inpatient, Hospital Outpatient, Emergency Room - Hospital, Ambulatory Surgical Center