N18.9 Chronic kidney disease, unspecified

The ICD-10-CM code for Chronic kidney disease, unspecified is N18.9 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

14: Diseases of the genitourinary system (N00-N99)

Section

N17-N19: Acute kidney failure and chronic kidney disease (N17-N19)

Category N18

11 codes (9 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to N18.9:

• Retinitis › renal
• Neuropathy, neuropathic › uremic
• Retinitis › albuminurica
• Apoplexia, apoplexy, apoplectic › uremic
• Glomerulonephritis › sclerosing, diffuse
• Syndrome › uremia, chronic
• Pericarditis (with decompensation) (with effusion) › uremic
• Paralysis, paralytic (complete) (incomplete) › uremic

Inclusion Terms

• Chronic renal disease
• Chronic renal failure NOS
• Chronic renal insufficiency
• Chronic uremia NOS
• Diffuse sclerosing glomerulonephritis NOS

U.S. Hospital Utilization

• An estimated 997,415 U.S. inpatient stays in 2023 included N18.9 among the documented diagnoses.
• 145 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Prevalence & Statistics

• More than 1 in 10 U.S. adults aged 18 or older (14%, about 37 million people) were estimated to have chronic kidney disease (CKD), based on August 2021-August 2023 NHANES data. (CDC Chronic Kidney Disease in the United States, August 2021-August 2023)

Official Coding Guidelines

CKD staging and code assignment (N18.-)

The ICD-10-CM classifies CKD based on severity. The severity of CKD is designated by stages 1-5. Stage 2, code N18.2, equates to mild CKD; stage 3, codes N18.30-N18.32, equate to moderate CKD; and stage 4, code N18.4, equates to severe CKD. Code N18.6, End stage renal disease (ESRD), is assigned when the provider has documented end- stage renal disease (ESRD).

CKD stage plus ESRD: assign N18.6 only

If both a stage of CKD and ESRD are documented, assign code N18.6 only.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)
• CDC Chronic Kidney Disease in the United States (August 2021-August 2023)