ICD-10-CM 2027
ICD-10 code for cognitive deficiency
From the official ICD-10-CM alphabetic index entry “Deficiency, deficient › cognitive”. Page updated September 29, 2026.
About coding cognitive deficiency
The ICD-10-CM code for cognitive deficiency is F09 (Unspecified mental disorder due to known physiological condition).
Don't report F09 together with the conditions in its Excludes1 note: mild neurocognitive disorder due to known physiological condition (F06.7-) and psychosis NOS (F29).
Code first: the underlying physiological condition.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Don't confuse with (Excludes1 for F09)
Common questions about cognitive deficiency ICD-10 codes
What is the ICD-10 code for cognitive deficiency?
- F09 — Unspecified mental disorder due to known physiological condition.
Is F09 billable?
- Yes. F09 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can F09 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict F09 as a principal diagnosis.
Is F09 a CC or MCC?
- No. F09 is neither a CC nor an MCC under MS-DRG v44.0.