N17.9 ICD-10-CM Code: Acute kidney failure, unspecified
N17.9 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · HCC Buddy coding tools
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FY 2026 Apr update / Diseases of the genitourinary system (N00-N99) / Acute kidney failure and chronic kidney disease (N17-N19)
N17.9
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAcute kidney failure, unspecified
A sudden loss of kidney function where the specific cause or type is not documented or identified. This requires urgent medical treatment.
Buddy Insight
Unspecified acute kidney failure represents sudden onset kidney dysfunction without documented specific etiology or type, indicating critical illness requiring immediate intervention.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
MappedHCC 135
RAF 0.435
ACA/HHS
N/A—
Not mapped
ESRD/PACE
MappedHCC 135
RAF 0.000
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Acute kidney injury (nontraumatic)
Excludes 2
Official- traumatic kidney injury (S37.0-)
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for N17.9 in this effective period.
Excludes 1
Official- posttraumatic renal failure (T79.5)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for N17.9 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for N17.9 in this effective period.
Code Also
Official- associated underlying condition
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 N17.9 an HCC code?
Yes. N17.9 maps to Acute Renal Failure under the V24 model but is not retained in V28.
- Code
- N17.9
- Description
- Acute kidney failure, unspecified
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
Work N17.9 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for N17.9
For N17.9 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed N17.9 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
N17.9 is the ICD-10-CM diagnosis code for acute kidney failure, unspecified. A sudden loss of kidney function where the specific cause or type is not documented or identified. This requires urgent medical treatment. N17.9 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).
Under the older CMS-HCC V24 model, N17.9 maps to Acute Renal Failure (HCC 135) with a community, non-dual, aged base RAF weight of 0.435. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This is a non-specific code; use only when the type of acute kidney failure cannot be determined from the medical record. Because N17.9 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for N17.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a non-specific code; use only when the type of acute kidney failure cannot be determined from the medical record
- •Query the provider if possible to obtain more specific information about the cause (prerenal, intrinsic, or postrenal) to assign a more specific code
Clinical Significance
Unspecified acute kidney failure represents sudden onset kidney dysfunction without documented specific etiology or type, indicating critical illness requiring immediate intervention. This diagnosis captures acute renal failure when specific classification details are not available but acute nature is established.
Documentation Requirements
- ✓Acute onset of kidney failure clearly documented
- ✓Laboratory values showing rapid deterioration in kidney function
- ✓Clinical evidence supporting acute rather than chronic process
- ✓Documentation of why specific type cannot be determined
- ✓Treatment interventions and patient response
- ✓Assessment for potential reversible causes
- ✓Monitoring plan for kidney function recovery
Excludes 2, Not included here, may code separately
- traumatic kidney injury (S37.0-)