2027 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 884. Coders also document this condition as amnestic disorder. 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 2027.
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 2027 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
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to F04: its own notes plus those printed at block F01-F09 and Chapter 5. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- disorders of psychological development
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Korsakov's psychosis or syndrome, nonalcoholic
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Code First
The underlying condition named in the note is sequenced before this code.
- the underlying physiological condition
Notes
General instructions on how these codes are used.
- This block comprises a range of mental disorders grouped together on the basis of their having in common a demonstrable etiology in cerebral disease, brain injury, or other insult leading to cerebral dysfunction. The dysfunction may be primary, as in diseases, injuries, and insults that affect the brain directly and selectively; or secondary, as in systemic diseases and disorders that attack the brain only as one of the multiple organs or systems of the body that are involved.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name F04, its category, or a range that includes it.
Applicable To 1
These notes mention F04.
- O99.34 Other mental disorders complicating pregnancy, childbirth, and the puerperium
Excludes1 1
These codes carry an Excludes1 note naming F04: they are not reported together with it, unless the two conditions are unrelated.
- R41.3 Other amnesiaamnestic disorder due to known physiologic condition (F04)
Excludes2 3
These codes carry an Excludes2 note naming F04: its condition is not part of those codes, and both may be reported when the patient has both.
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, 2026 through September 30, 2027.
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, 2026 through September 30, 2027.
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 1.5998. Higher weights mean higher Medicare reimbursement.
Can F04 be reported with R41.3?
Not as a rule. The Excludes1 note on F04 lists "amnesia NOS (R41.3)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is coded first with F04?
The Code First note reads: the underlying physiological condition. When one of these applies, it is sequenced before F04.
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).
