MCMCB Pro
N21

N21Calculus of lower urinary tract

Non-billable headerICD-10-CM

N21 is a non-billable header ICD-10-CM code for calculus of lower urinary tract. It cannot be billed on its own: choose one of the more specific child codes below.

Includes

Conditions this code covers.

  • calculus of lower urinary tract with cystitis and urethritis

Risk adjustment

N21 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead N21

4 child codes. Green means billable.

Questions about N21

Is N21 a billable ICD-10-CM code?
No. N21 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does N21 sit in the tabular list?
Diseases of the genitourinary system (N00-N99), in the block Urolithiasis (N20-N23).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.