F19 vs R41.3
F19 and R41.3 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on R41.3
amnestic syndrome due to psychoactive substance use (F10-F19 with 5th character .6)
F19
Other psychoactive substance related disorders
Not billable
- Chapter 5
- Mental, Behavioral and Neurodevelopmental disorders
- Section
- F10-F19
Use when the record says
- polysubstance drug use (indiscriminate drug use)
R41.3
Other amnesia
Billable
- Chapter 18
- Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
- Section
- R40-R46
Use when the record says
- Amnesia NOS
- Memory loss NOS
Indexed under
- Amnesia
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027