2026 ICD-10-CM Diagnosis Code N17.9Acute kidney failure, unspecified
ICD-10-CM Codes›N00–N99›N17-N19›N17
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
N17.9 is a billable ICD-10-CM diagnosis code for acute kidney failure, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 673 through 675, 682 through 684, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 301 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acute and unspecified renal failure.
N17.9 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 135 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 135, ESRD (V21) category 135, and ESRD (V24) category 135 for payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
N17.9 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute hepatic failure
- Acute kidney failure stage 1
- Acute kidney failure stage 2
- Acute kidney failure stage 3
- Acute kidney injury
- Acute kidney injury caused by contrast agent
- Acute kidney injury due to COVID-19
- Acute kidney injury due to hypovolemia
- Acute kidney injury due to sepsis
- Acute kidney injury following administration of contrast media
- Acute nontraumatic kidney injury
- Acute renal failure caused by angiotensin-converting-enzyme inhibitor
- Acute renal failure due to procedure
- Acute renal failure on dialysis
- Acute renal failure with oliguria
- Acute-on-chronic renal failure
- Angiotensin-converting-enzyme inhibitor adverse reaction
- Hepatorenal syndrome
- Hepatorenal syndrome with acute kidney injury
- Intra-renal acute kidney injury
- Nephrotoxic acute renal failure
- Postprocedural acute renal failure
- Post-renal acute kidney injury
- Prerenal renal failure
- Transient acute renal failure
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Acute kidney injury (nontraumatic)
Type 2 Excludes
- traumatic kidney injury S37.0
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Injury See Also: specified injury type; T14.90
acute (nontraumatic) N17.9
Necrosis, necrotic (ischemic) See Also: Gangrene;
acute N17.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Acute Kidney Injury
abrupt reduction in kidney function. acute kidney injury encompasses the entire spectrum of the syndrome including acute kidney failure; acute kidney tubular necrosis; and other less severe conditions.Hepatorenal Syndrome
functional kidney failure in patients with liver disease, usually liver cirrhosis or portal hypertension (hypertension, portal), and in the absence of intrinsic renal disease or kidney abnormality. it is characterized by intense renal vasculature constriction, reduced renal blood flow, oliguria, and sodium retention.
Patient EducationClinical
Kidney Failure
Healthy kidneys clean your blood by removing excess fluid, minerals, and wastes. They also make hormones that keep your bones strong and your blood healthy. But if the kidneys are damaged, they don't work properly. Harmful wastes can build up in your body. Your blood pressure may rise.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert N17.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About N17.9Overview
What is the ICD-10 code for acute kidney failure, unspecified?
The ICD-10-CM code for acute kidney failure, unspecified is N17.9 (sometimes written as N179). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is N17.9 (Acute kidney failure) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report acute kidney failure, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does N17.9 group to?
When acute kidney failure, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 673, 674, 675, 682, 683, 684, 791, 793, with relative weights from 0.6003 to 4.2016 depending on complications. Higher weights mean higher Medicare reimbursement.
Is N17.9 a CC or MCC?
CMS lists N17.9 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 301 closely related codes in its exclusion list.
What is the ICD-9 equivalent of N17.9?
Under the General Equivalence Mappings, acute kidney failure, unspecified converts to ICD-9-CM 584.9 (acute kidney failure NOS). The mapping is a direct match.
Does N17.9 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage. N17.9 mapped to HCC 135 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 135 (Acute Renal Failure), ESRD (V21) category 135 (Acute Renal Failure), and ESRD (V24) category 135 (Acute Renal Failure).
