What is ICD-10 code N18.2?

N18.2 is the ICD-10-CM diagnosis code for Chronic kidney disease, stage 2 (mild). Stage 2 chronic kidney disease where kidney function is mildly decreased with a GFR of 60-89, and there is evidence of kidney damage. N18.2 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. N18.2 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. N18.2 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. N18.2 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does N18.2 map to under V28?

N18.2 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

What RAF reference is published for N18.2?

N18.2 has no V28 reference coefficient because the final FY2026 source verifies no payable V28 mapping.

What is the V28 vs V24 difference for N18.2?

N18.2 has verified no payable V28 mapping in the final FY2026 source. Select a historical effective period before making any V24 comparison.

2026 ICD-10-CM N18.2: Chronic kidney disease, stage 2 (mild)

N18.2 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC Buddy coding tools

ICD-10-CM Code View

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Code lookupN18.2

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the genitourinary system (N00-N99) / Acute kidney failure and chronic kidney disease (N17-N19)

N18.2

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Chronic kidney disease, stage 2 (mild)

Stage 2 chronic kidney disease where kidney function is mildly decreased with a GFR of 60-89, and there is evidence of kidney damage.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

N18Chronic kidney disease (CKD)N18.2Chronic kidney disease, stage 2 (mild)

Inclusion Terms

Official

No inclusion terms are included in this display for N18.2. Check the code and parent instructions in the Code Book.

Excludes 2

Official

certain conditions originating in the perinatal period (P04-P96)Inherited from N00-N99, N17-N19
certain infectious and parasitic diseases (A00-B99)Inherited from N00-N99, N17-N19
complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from N00-N99, N17-N19
congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)Inherited from N00-N99, N17-N19
endocrine, nutritional and metabolic diseases (E00-E88)Inherited from N00-N99, N17-N19
injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from N00-N99, N17-N19
neoplasms (C00-D49)Inherited from N00-N99, N17-N19
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from N00-N99, N17-N19
congenital renal failure (P96.0)Inherited from N00-N99, N17-N19
drug- and heavy-metal-induced tubulo-interstitial and tubular conditions (N14.-)Inherited from N00-N99, N17-N19
extrarenal uremia (R39.2)Inherited from N00-N99, N17-N19
hemolytic-uremic syndrome (D59.3-)Inherited from N00-N99, N17-N19
hepatorenal syndrome (K76.7)Inherited from N00-N99, N17-N19
postpartum hepatorenal syndrome (O90.41)Inherited from N00-N99, N17-N19
posttraumatic renal failure (T79.5)Inherited from N00-N99, N17-N19
prerenal uremia (R39.2)Inherited from N00-N99, N17-N19
renal failure complicating abortion or ectopic or molar pregnancy (O00-O07, O08.4)Inherited from N00-N99, N17-N19
renal failure following labor and delivery (O90.41)Inherited from N00-N99, N17-N19
renal failure postprocedural (N99.0)Inherited from N00-N99, N17-N19

Related Codes

Official

N18.1Chronic kidney disease, stage 1 N18.3Chronic kidney disease, stage 3 (moderate)N18.4Chronic kidney disease, stage 4 (severe)N18.5Chronic kidney disease, stage 5 N18.6End stage renal disease

Includes

Official

No Includes notes are included in this display for N18.2. Check the code and parent instructions in the Code Book.

Excludes 1

Official

No Excludes 1 notes are included in this display for N18.2. Check the code and parent instructions in the Code Book.

Code First

Official

any associated:Inherited from N18
diabetic chronic kidney disease (E08.22, E09.22, E10.22, E11.22, E13.22)Inherited from N18
hypertensive chronic kidney disease (I12.-, I13.-)Inherited from N18

Use Additional

Official

code, if applicable, to identify:Inherited from N18
associated cachexia (E88.A)Inherited from N18
kidney transplant status (Z94.0)Inherited from N18

Code Also

Official

No Code Also instructions are included in this display for N18.2. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Documentation must support CKD stage 2 with eGFR 60-89 plus evidence of kidney damage over at least 3 months. The provider must explicitly diagnose CKD; a single lab value in the mildly reduced range does not establish the diagnosis alone.

N18.2 is not an HCC and the 'CKD stage 2' label can be misread, some coders mistakenly treat it like N18.3 or higher. It carries no V28 risk adjustment weight, and a stage upgrade requires the provider to document progression.

Chart completeness matters for the underlying etiology, pair with diabetes, hypertension, or other causal code when documented.

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is N18.2 an HCC code?

No. N18.2 is a billable ICD-10-CM code with no mapping under the CMS-HCC V28 or V24 community payment models, and none under the ESRD, Part D RxHCC, or HHS-HCC models.

Code: N18.2
Description: Chronic kidney disease, stage 2 (mild)
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

Coder workflow notes

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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

N18.2 is the ICD-10-CM diagnosis code for chronic kidney disease, stage 2 (mild). Stage 2 chronic kidney disease where kidney function is mildly decreased with a GFR of 60-89, and there is evidence of kidney damage. N18.2 sits in the ICD-10-CM chapter for diseases of the genitourinary system (n00-n99), within the section covering acute kidney failure and chronic kidney disease (n17-n19).

N18.2 is a billable ICD-10-CM code, but the current payload does not show a mapping under the CMS-HCC V28 or V24 community payment models, and none under the ESRD, Part D RxHCC, or HHS-HCC models. Do not assign risk adjustment value from this page when no source-backed mapping is shown; verify the applicable model and payment year.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for N18.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Documentation must support CKD stage 2 with eGFR 60-89 plus evidence of kidney damage over at least 3 months. The provider must explicitly diagnose CKD; a single lab value in the mildly reduced range does not establish the diagnosis alone.
•N18.2 is not an HCC and the 'CKD stage 2' label can be misread, some coders mistakenly treat it like N18.3 or higher. It carries no V28 risk adjustment weight, and a stage upgrade requires the provider to document progression.
•Chart completeness matters for the underlying etiology, pair with diabetes, hypertension, or other causal code when documented.