DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

N21 Calculus of lower urinary tract

  • Header · not billable

N21 is not billable. The category heads 4 billable codes in FY2027: the 4 codes directly below it.

Index → code

  • Cystolithiasis → N21.0
  • Urethrolithiasis (with colic or infection) → N21.1
  • Stone(s)urethra (impacted) → N21.1

Where it sits

  1. Chapter 14 Diseases of the genitourinary system (N00-N99)
  2. N20-N23 Urolithiasis (N20-N23)
  3. N21 Calculus of lower urinary tract
Billable codes
4
Subdivisions
4
CC / MCC codes
0 / 0
HCC V28 codes
0
New FY2027
0
Index entries
19

Codes in N21

  1. N21.0
    Calculus in bladder
    Billable
    Inclusion terms 2, Excludes2 1

    Inclusion terms

    • Calculus in diverticulum of bladder
    • Urinary bladder stone

    Excludes2

    • staghorn calculus (N20.0) N20.0
  2. N21.1
    Calculus in urethra
    Billable
    Excludes2 1

    Excludes2

    • calculus of prostate (N42.0) N42.0
  3. N21.8
    Other lower urinary tract calculus
    Billable
  4. N21.9
    Calculus of lower urinary tract, unspecified
    Billable
    Excludes1 1

    Excludes1

    • calculus of urinary tract NOS (N20.9) N20.9

Sources of each column.

Instructions

At N21

Includes

  • calculus of lower urinary tract with cystitis and urethritis

Notes that also apply

Chapter 14 instructions (Excludes2 8): printed on the chapter 14 page.

Index entries

  • Cystolithiasis → N21.0
  • Urethrolithiasis (with colic or infection) → N21.1
  • Calculus, calculi, calculousbladder (encysted) (impacted) (urinary) (diverticulum) → N21.0
  • Calculus, calculi, calculouscystic → N21.0
  • Calculus, calculi, calculousvesical (impacted) → N21.0
  • Cystitis (exudative) (hemorrhagic) (septic) (suppurative)calculous → N21.0
  • Stone(s)bladder (diverticulum) → N21.0
  • Calculus, calculi, calculousurethra (impacted) → N21.1
  • Stone(s)urethra (impacted) → N21.1
  • Urethritis (anterior) (posterior)calculous → N21.1
  • Calculus, calculi, calculousileal conduit → N21.8
  • Calculus, calculi, calculoussuburethral → N21.8
  • Calculus, calculi, calculousdiverticulumbladder → N21.0
  • Stone(s)urinary (duct) (impacted) (passage)bladder (diverticulum) → N21.0
  • Colic (bilious) (infantile) (intestinal) (recurrent) (spasmodic)urethraldue to calculus → N21.1
  • Stone(s)urinary (duct) (impacted) (passage)specified NEC → N21.8
  • Calculus, calculi, calculousurinary (duct) (impacted) (passage) (tract)lower → N21.9
  • Stone(s)urinary (duct) (impacted) (passage)lower tract → N21.9
  • Calculus, calculi, calculousurinary (duct) (impacted) (passage) (tract)lowerspecified NEC → N21.8

NCHS Alphabetic Index. Index first, then the Tabular List.

Hierarchy