Is N20.1 a billable ICD-10-CM code?

Yes. N20.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does N20.1 sit in the tabular list?

Diseases of the genitourinary system (N00-N99), in the block Urolithiasis (N20-N23).

What cannot be coded together with N20.1?

N20.1 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above N20.1 (N20) and apply to it just the same.

N20.1

N20.1 — Calculus of ureter

Billable / specific codeICD-10-CM

N20.1 is a billable, specific ICD-10-CM code for calculus of ureter. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Calculus of the ureteropelvic junction
Ureteric stone

Excludes1 inherited from the categories above N20.1

These are not written on N20.1, but they bind it: a note on a category applies to every code beneath it. Billing N20.1 with anything listed here is a denial.

Written on N20 — Calculus of kidney and ureter

nephrocalcinosis (E83.59)
that with hydronephrosis (N13.2)

Risk adjustment

N20.1 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

N20.1 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 N20.1 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 N20.1.

Calculus, calculi, calculous›ureter(impacted) (recurrent)
Calculus, calculi, calculous›ureteropelvic junction
Ureteritis›due to calculus

Code history

N20.1 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share N20. If N20.1 is not quite right, the correct code is usually one of these.

Questions about N20.1

Is N20.1 a billable ICD-10-CM code?: Yes. N20.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does N20.1 sit in the tabular list?: Diseases of the genitourinary system (N00-N99), in the block Urolithiasis (N20-N23).
What cannot be coded together with N20.1?: N20.1 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above N20.1 (N20) and apply to it just the same.