N21 Calculus of lower urinary tract

Category / Non-billable header 4 subcodes

Block: Urolithiasis (N20-N23)

Includes

  • calculus of lower urinary tract with cystitis and urethritis

Subcodes

Subcodes are listed below for reference. Detail pages are not available for chapters 11–22.

Code Description Billable
N21..0 Calculus in bladder Yes
N21..1 Calculus in urethra Yes
N21..8 Other lower urinary tract calculus Yes
N21..9 Calculus of lower urinary tract, unspecified Yes

Last reviewed: September 2026