F04
BillableAmnestic disorder due to known physiological condition
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F04 an HCC code?
Yes. F04 maps to Dementia Without Complication under the V24 model but is not retained in V28.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.
MEAT Criteria for F04
For F04to 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.
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