2026 ICD-10-CM Diagnosis Code F04Amnestic disorder due to known physiological condition
ICD-10-CM Codes›F01–F99›F01-F09›F04
- Billable — Valid for Submission
- Not Chronic
F04 is a billable ICD-10-CM diagnosis code for amnestic disorder due to known physiological condition. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 884. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neurocognitive disorders.
F04 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 52 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 ESRD (V21) category 52, ESRD (V24) category 52, and RxHCC Part D (V08) category 112 for payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
F04 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.
- Amnestic disorder
- Confabulation
- Delusional memories
- Distortion of memory
- Fantastical confabulation
- Momentary confabulation
- Non-alcoholic Korsakoff's psychosis
- Organic amnesia of language
- Organic memory impairment
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Korsakov's psychosis or syndrome, nonalcoholic
Code First
- the underlying physiological condition
Type 1 Excludes
Type 2 Excludes
- 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
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.
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
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.
Amentia See: Disability, intellectual;
Disease, diseased See Also: Syndrome;
Disorder (of) See Also: Disease;
Syndrome See Also: Disease;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Memory
Every day, you have different experiences and you learn new things. Your brain cannot store all of that information, so it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few seconds or minutes.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert F04 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About F04Overview
What is the ICD-10 code for amnestic disorder due to known physiological condition?
The ICD-10-CM code for amnestic disorder due to known physiological condition is F04. It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is F04 (Amnestic disorder due to known physiological condition) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report amnestic disorder due to known physiological condition on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does F04 group to?
When amnestic disorder due to known physiological condition is the principal diagnosis on an inpatient stay, it groups to MS-DRG 884 (organic Disturbances and Intellectual Disability), which carries a relative weight of 1.6089. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of F04?
Under the General Equivalence Mappings, amnestic disorder due to known physiological condition converts to ICD-9-CM 294.0 (amnestic disord oth dis). The mapping is approximate, so confirm the match fits the documentation.
Does F04 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage. F04 mapped to HCC 52 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 ESRD (V21) category 52 (Dementia Without Complication), ESRD (V24) category 52 (Dementia Without Complication), and RxHCC Part D (V08) category 112 (Dementia, Except Alzheimer's Disease).
