N18.1 — Chronic kidney disease, stage 1
N18.1 is a billable, specific ICD-10-CM code for chronic kidney disease, stage 1. It is valid for submission on a claim.
Other codes that can never be billed with N18.1
These codes carry an Excludes1 note pointing at N18.1. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading N18.1 alone.
- N19Unspecified kidney failure
Risk adjustment
N18.1 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
N18.1 is named in 32 Medicare coverage policies — 32 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52996Billing and Coding: Routine Foot Care
- A55336Billing and Coding: Retroperitoneal Ultrasound
- A56232Billing and Coding: Foot Care
- A56421Billing and Coding: CT of the Abdomen and Pelvis
How N18.1 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 N18.1.
- Disease, diseased›kidney›chronic›stage 1
There’s a guided path to this code
Not sure N18.1 is the right one? Answer a few questions about what the chart documents and we’ll walk you to the code that follows from it.
The condition this code belongs to
Every code for the condition on one page, which one applies when, and the mistake coders make with it.
Code history
N18.1 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 N18. If N18.1 is not quite right, the correct code is usually one of these.
Questions about N18.1
- Is N18.1 a billable ICD-10-CM code?
- Yes. N18.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does N18.1 sit in the tabular list?
- Diseases of the genitourinary system (N00-N99), in the block Acute kidney failure and chronic kidney disease (N17-N19).