N20.0 — Calculus of kidney
N20.0 is a billable, specific ICD-10-CM code for calculus of kidney. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Nephrolithiasis NOS
- Renal calculus
- Renal stone
- Staghorn calculus
- Stone in kidney
Other codes that can never be billed with N20.0
These codes carry an Excludes1 note pointing at N20.0. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading N20.0 alone.
- E79Disorders of purine and pyrimidine metabolism
Risk adjustment
N20.0 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.
Medicare coverage
N20.0 is named in 6 Medicare coverage policies — 6 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A55336Billing and Coding: Retroperitoneal Ultrasound
- A56421Billing and Coding: CT of the Abdomen and Pelvis
- A57718Billing and Coding: Vitamin D Assay Testing
- A57736Billing and Coding: Vitamin D Assay Testing
How N20.0 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to N20.0.
- Calculus, calculi, calculous›kidney(impacted) (multiple) (pelvis) (recurrent) (staghorn)
- Calculus, calculi, calculous›pyelitis(impacted) (recurrent)
- Stone›kidney
- Stone›renal
- Abscess›kidney›with calculus
- Calculus, calculi, calculous›diverticulum›kidney
- Infection, infected, infective›kidney›with calculus
Related codes at this level
Codes that share N20. If N20.0 is not quite right, the correct code is usually one of these.
Questions about N20.0
- Is N20.0 a billable ICD-10-CM code?
- Yes. N20.0 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does N20.0 sit in the tabular list?
- Diseases of the genitourinary system (N00-N99), in the block Urolithiasis (N20-N23).