Excludes1 pair
F06- vs F09
F06 and F09 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on F09
mild neurocognitive disorder due to known physiological condition (F06.7-)
F06
Other mental disorders due to known physiological condition
Not billable
- Chapter 5
- Mental, Behavioral and Neurodevelopmental disorders
- Section
- F01-F09
Use when the record says
- mental disorders due to endocrine disorder
- mental disorders due to exogenous hormone
- mental disorders due to exogenous toxic substance
- mental disorders due to primary cerebral disease
- mental disorders due to somatic illness
- mental disorders due to systemic disease affecting the brain
F09
Unspecified mental disorder due to known physiological condition
BillableUnspecified
- Chapter 5
- Mental, Behavioral and Neurodevelopmental disorders
- Section
- F01-F09
Use when the record says
- Mental disorder NOS due to known physiological condition
- Organic brain syndrome NOS
- Organic mental disorder NOS
- Organic psychosis NOS
- Symptomatic psychosis NOS
Indexed under
- Deficiency, deficient › cognitive
- Disorder › cognitive
- Organic › brain syndrome
- Organic › mental disorder
- Organic › psychosis
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