Is N26.1 a billable ICD-10-CM code?

Yes. N26.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does N26.1 sit in the tabular list?

Diseases of the genitourinary system (N00-N99), in the block Other disorders of kidney and ureter (N25-N29).

What cannot be coded together with N26.1?

N26.1 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 N26.1 (N26) and apply to it just the same.

N26.1

N26.1 — Atrophy of kidney (terminal)

Billable / specific codeICD-10-CM

N26.1 is a billable, specific ICD-10-CM code for atrophy of kidney (terminal). It is valid for submission on a claim.

Excludes1 inherited from the categories above N26.1

These are not written on N26.1, but they bind it: a note on a category applies to every code beneath it. Billing N26.1 with anything listed here is a denial.

Written on N26 — Unspecified contracted kidney

contracted kidney due to hypertension (I12.-)
diffuse sclerosing glomerulonephritis (N05.8.-)
hypertensive nephrosclerosis (arteriolar) (arteriosclerotic) (I12.-)
small kidney of unknown cause (N27.-)

Risk adjustment

N26.1 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

N26.1 is named in 4 Medicare coverage policies — 4 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
A56747Billing and Coding: Magnetic Resonance Angiography (MRA)
A57189Billing and Coding: Serum Magnesium
A57591Billing and Coding: Non-Invasive Abdominal / Visceral Vascular Studies

How N26.1 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 N26.1.

Atrophy, atrophic›kidney(senile) (terminal)
Atrophy, atrophic›renal

Code history

N26.1 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 N26. If N26.1 is not quite right, the correct code is usually one of these.

Questions about N26.1

Is N26.1 a billable ICD-10-CM code?: Yes. N26.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does N26.1 sit in the tabular list?: Diseases of the genitourinary system (N00-N99), in the block Other disorders of kidney and ureter (N25-N29).
What cannot be coded together with N26.1?: N26.1 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 N26.1 (N26) and apply to it just the same.