FY2027 ICD-10-CM reference
N18.4: Chronic kidney disease, stage 4 (severe)
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Chronic kidney disease, stage 4 (severe). The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
CMS-HCC V28
- HCC 327: Chronic Kidney Disease, Severe (Stage 4) · RAF 0.514, Community Non-Dual Aged (CNA)
Payment year 2027, 2026 dates of service. HCC from the CMS 2027 Initial ICD-10-CM Mappings; RAF from the CMS-HCC V28 relative factors. For 2027 dates of service, CMS has not yet published the payment year 2028 mappings.
CMS-HCC V24
Not used for payment year 2027 Medicare Advantage payment
ESRD
- HCC 137: Chronic Kidney Disease/Severe (Stage 4)
Coefficient pending: payment year 2027 coefficients for this model are not yet verified, so no RAF is shown. Mapping: PY2026 CMS mapping; CMS 2027 initial file unchanged.
PACE
Source verification pending
RxHCC
- HCC 263: Chronic Kidney Disease Stage 4
Coefficient pending: payment year 2027 coefficients for this model are not yet verified, so no RAF is shown. Mapping: PY2026 CMS mapping; CMS 2027 initial file unchanged.
HHS-HCC
- HCC 188: Chronic Kidney Disease, Severe (Stage 4)
RAF not applicable: HHS-HCC weights vary by metal level. Mapping: HHS-HCC 2026 benefit year.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Excludes2
certain conditions originating in the perinatal period (P04-P96)
Source: N00-N99 (chapter, inherited).
Excludes2
certain infectious and parasitic diseases (A00-B99)
Source: N00-N99 (chapter, inherited).
Excludes2
complications of pregnancy, childbirth and the puerperium (O00-O9A)
Source: N00-N99 (chapter, inherited).
Excludes2
congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
Source: N00-N99 (chapter, inherited).
Excludes2
endocrine, nutritional and metabolic diseases (E00-E88)
Source: N00-N99 (chapter, inherited).
Excludes2
injury, poisoning and certain other consequences of external causes (S00-T88)
Source: N00-N99 (chapter, inherited).
Excludes2
neoplasms (C00-D49)
Source: N00-N99 (chapter, inherited).
Excludes2
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: N00-N99 (chapter, inherited).
Excludes2
congenital renal failure (P96.0)
Source: N17-N19 (section, inherited).
Excludes2
drug- and heavy-metal-induced tubulo-interstitial and tubular conditions (N14.-)
Source: N17-N19 (section, inherited).
Excludes2
extrarenal uremia (R39.2)
Source: N17-N19 (section, inherited).
Excludes2
hemolytic-uremic syndrome (D59.3-)
Source: N17-N19 (section, inherited).
Excludes2
hepatorenal syndrome (K76.7)
Source: N17-N19 (section, inherited).
Excludes2
postpartum hepatorenal syndrome (O90.41)
Source: N17-N19 (section, inherited).
Excludes2
posttraumatic renal failure (T79.5)
Source: N17-N19 (section, inherited).
Excludes2
prerenal uremia (R39.2)
Source: N17-N19 (section, inherited).
Excludes2
renal failure complicating abortion or ectopic or molar pregnancy (O00-O07, O08.4)
Source: N17-N19 (section, inherited).
Excludes2
renal failure following labor and delivery (O90.41)
Source: N17-N19 (section, inherited).
Excludes2
renal failure postprocedural (N99.0)
Source: N17-N19 (section, inherited).
Code first
any associated:
Source: N18 (category, inherited).
Code first
diabetic chronic kidney disease (E08.22, E09.22, E10.22, E11.22, E13.22)
Source: N18 (category, inherited).
Code first
hypertensive chronic kidney disease (I12.-, I13.-)
Source: N18 (category, inherited).
Instructional note
code, if applicable, to identify:
Source: N18 (category, inherited).
Instructional note
associated cachexia (E88.A)
Source: N18 (category, inherited).
Instructional note
kidney transplant status (Z94.0)
Source: N18 (category, inherited).
Compare the FY2027 additions, removals and billable-status changes
What does N18.4 mean in FY2027?
The official ICD-10-CM descriptor is Chronic kidney disease, stage 4 (severe). The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is N18.4 billable in FY2027?
The FY2027 order file marks N18.4 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does N18.4 map to an HCC?
In the CMS 2027 Initial ICD-10-CM Mappings (payment year 2027, 2026 dates of service), N18.4 maps to CMS-HCC V28 HCC 327 (Chronic Kidney Disease, Severe (Stage 4)). For 2027 dates of service, CMS has not yet published the payment year 2028 mappings. Under the PY2026 CMS mapping; CMS 2027 initial file unchanged: ESRD HCC 137; RxHCC HCC 263. Coefficients for these models are pending verification for payment year 2027. HHS-HCC: HCC 188 under the HHS-HCC 2026 benefit year mapping (no RAF; HHS-HCC weights vary by metal level). CMS-HCC V24: not used for payment year 2027 Medicare Advantage payment (CMS CY 2027 Rate Announcement). The PACE mapping is still pending verification for FY2027.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.
Review the FY2026 April edition