F04 ICD-10-CM Code: Amnestic disorder due to known physiological condition
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Mental disorders due to known physiological conditions (F01-F09)
F04
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAmnestic disorder due to known physiological condition
Memory loss or difficulty forming new memories caused by a known medical condition, injury, or physical illness rather than a primary psychiatric disorder.
Buddy Insight
Amnestic disorder due to known physiological condition represents a specific memory impairment caused by an identified medical condition such as traumatic brain injury, cerebrovascular disease, or substance exposure.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
MappedHCC 52
RAF 0.346
ACA/HHS
N/A—
Not mapped
ESRD/PACE
MappedHCC 52
RAF 0.042
RXHCC
MappedHCC 112
Not separately weighted
Code Book Path
Inclusion Terms
Official- Korsakov's psychosis or syndrome, nonalcoholic
Excludes 2
Official- alcohol-induced or unspecified Korsakov's syndrome (F10.26, F10.96)
- Korsakov's syndrome induced by other psychoactive substances (F13.26, F13.96, F19.16, F19.26, F19.96)
Related Child Codes
ICD-10-CM does not list child codes under F04 for this display context.
Includes
OfficialICD-10-CM does not list Includes notes for F04 in this effective period.
Excludes 1
Official- amnesia NOS (R41.3)
- anterograde amnesia (R41.1)
- dissociative amnesia (F44.0)
- retrograde amnesia (R41.2)
Code First
Official- the underlying physiological condition
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for F04 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for F04 in this effective period.
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 F04 an HCC code?
Yes. F04 maps to Dementia Without Complication under the V24 model but is not retained in V28.
- Code
- F04
- Description
- Amnestic disorder due to known physiological condition
- 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 F04 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for F04
For F04 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 F04 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
Get the V28 RAF + MEAT cheat sheet
One printable page: confirm a code's V28 HCC status, its RAF weight, and the MEAT your note needs to make it stick. Free, no card.
Free PDF. No card. Unsubscribe anytime.
What This Code Means
F04 is the ICD-10-CM diagnosis code for amnestic disorder due to known physiological condition. Memory loss or difficulty forming new memories caused by a known medical condition, injury, or physical illness rather than a primary psychiatric disorder. F04 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering mental disorders due to known physiological conditions (f01-f09).
Under the older CMS-HCC V24 model, F04 maps to Dementia Without Complication (HCC 52) with a community, non-dual, aged base RAF weight of 0.346. 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.
Always identify and document the underlying physiological condition causing the amnestic disorder. Because F04 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 F04 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Always identify and document the underlying physiological condition causing the amnestic disorder
- •This code requires a known medical cause; if no cause is identified, use a different code
Clinical Significance
Amnestic disorder due to known physiological condition represents a specific memory impairment caused by an identified medical condition such as traumatic brain injury, cerebrovascular disease, or substance exposure. Unlike dementia, the cognitive deficit is primarily limited to memory function while other cognitive domains remain relatively intact. Accurate coding is important for differentiating from dementia and ensuring appropriate neuropsychological follow-up.
Documentation Requirements
- ✓Clear documentation of a significant memory impairment (anterograde and/or retrograde amnesia)
- ✓Identification of the underlying physiological condition causing the amnestic disorder
- ✓Evidence that the memory deficit is disproportionate to other cognitive functions (distinguishing from dementia)
- ✓Neuropsychological testing or cognitive assessment results supporting the diagnosis
- ✓Code the underlying physiological condition first, then assign F04 as an additional code
Excludes 1, Do NOT code together
Excludes 2, Not included here, may code separately
Code First
- the underlying physiological condition
Commonly Confused Codes
- •F03.x: Unspecified dementia; dementia involves global cognitive decline, not isolated memory loss
- •R41.1: Anterograde amnesia; use R41.1 for symptom-level coding when no underlying physiological cause is established
- •R41.2: Retrograde amnesia; symptom code for memory loss without established physiological cause
- •F10.26: Alcohol dependence with alcohol-induced persisting amnestic disorder; use when alcohol is the identified cause
- •F44.0: Dissociative amnesia; this is a psychological/dissociative condition, not due to a physiological cause