Is ICD-10-CM code N18 billable?

No, N18 (Chronic kidney disease (CKD)) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code N18 belong to?

N18 belongs to Chapter 14 of the ICD-10-CM tabular list: N00–N99 (Diseases of the Genitourinary System).

N18Not billable, use a more specific code below

Chronic kidney disease (CKD)

In Acute kidney failure and chronic kidney disease (N17-N19), chapter 14: Diseases of the Genitourinary System

9 billable codes under N18: 1 is an MCC, 2 are a CC; 6 map to HCC 326 (Chronic Kidney Disease, Stage 5), HCC 329 (Chronic Kidney Disease, Moderate (Stage 3, Except 3B)), HCC 327 (Chronic Kidney Disease, Severe (Stage 4)) and 1 more HCCs.A CC or MCC (major CC) is a secondary diagnosis that raises the MS-DRG payment. An HCC counts toward a Medicare Advantage patient's risk score.

Instructional notes

Code first: code the underlying condition first, then this code

any associated:
diabetic chronic kidney disease (E08.22, E09.22, E10.22, E11.22, E13.22)
hypertensive chronic kidney disease (I12.-, I13.-)

Use additional code: add a second code for this, listed after this one

code, if applicable, to identify:
associated cachexia (E88.A)
kidney transplant status (Z94.0)

Also applies, from Acute kidney failure and chronic kidney disease (N17-N19)

These notes sit on N17-N19 and apply to every code under it, including N18.

Excludes2: not included here, code separately if applicable

congenital renal failure (P96.0)
drug- and heavy-metal-induced tubulo-interstitial and tubular conditions (N14.-)
extrarenal uremia (R39.2)
hemolytic-uremic syndrome (D59.3-)
hepatorenal syndrome (K76.7)
postpartum hepatorenal syndrome (O90.41)
posttraumatic renal failure (T79.5)
prerenal uremia (R39.2)
renal failure complicating abortion or ectopic or molar pregnancy (O00-O07, O08.4)
renal failure following labor and delivery (O90.41)
renal failure postprocedural (N99.0)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Section I.C.14.a Chronic kidney disease (page 62), covers N18
Code CKD stage with N18 codes, using only N18.6 when ESRD is documented. After kidney transplant, CKD alone is not a complication: code the N18 stage plus Z94.0. Sequence CKD with other conditions per Tabular List conventions.

Read Section I.C.14 (page 62)

All codes under N18

N18 can't be used on a claim. Pick a billable code below; grey headings group them.

N18 MS-DRGs

This code does not group to an MS-DRG as a principal diagnosis.

Other codes that refer to N18

Notes on these codes point to N18.

D59.3 Code Also: chronic kidney disease (N18.-)
D63.1 Code First: underlying chronic kidney disease (CKD) (N18.-)
E20.810 Code Also: chronic kidney disease (N18.-)
I12 Includes: any condition in N18 and N26 - due to hypertension
I5A Code First: chronic kidney disease (CKD) (N18.-)
I75.81 Use Additional Code: code for any associated acute kidney failure and chronic kidney disease (N17.-, N18.-)
N19 Excludes1: chronic kidney disease (N18.-)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Chronic Kidney Disease

You have two kidneys, each about the size of your fist. Their main job is to filter your blood. They remove wastes and extra water, which become urine. They also keep the body's chemicals balanced, help control blood pressure, and make hormones.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.