N18.4
Chronic kidney disease, stage 4 (severe)
N18.4 (also written N184) is a billable ICD-10-CM diagnosis code for chronic kidney disease, stage 4 (severe). It is part of the FY2027 code set, effective October 1, 2026. It is one of the 9 codes in category N18 (Chronic kidney disease (CKD)). The Alphabetic Index lists it under 1 entry. Its coding notes include a Code first instruction, a Use additional code instruction and 19 Excludes2 entries.
Guidelines tips
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
Hypertension with heart disease and CKD goes to I13, not I11 or I12. An N18 code is added as a secondary code to give the CKD stage.
ESRD is assigned only when the provider documents it. If a CKD stage and ESRD are both documented, only N18.6 is assigned.
Code first
If the underlying condition listed here is present and known, sequence it first.
Use additional code
Add the listed code as a secondary code, if known.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (19 notes)
- 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)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Gastrointestinal tract and Genitourinary system clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026Hospital CC
Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 299 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CIPF Comorbidity
On the CMS IPF comorbidity list.
| Comorbidity category | Factor |
|---|---|
| Renal Failure, Chronic | 1.08 |
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 1 entry