ICDcodes.org
FY2027

F06 vs F09

F06 and F09 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 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 (of)
  • 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