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Compare/F29 vs F99

F29 vs F99

F29 (Unspecified psychosis not due to a substance or known physiological condition) compared with F99 (Mental disorder, not otherwise specified), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. F29 carries an Excludes1 note covering F99: “mental disorder NOS (F99)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

F29Unspecified psychosis not due to a substance or known physiological conditionF99Mental disorder, not otherwise specified
Billing statusBillableBillable
ClassificationF01-F99 — Mental, Behavioral and Neurodevelopmental Disorders (F01-F99)F01-F99 — Mental, Behavioral and Neurodevelopmental Disorders (F01-F99)
DefinitionUnspecified psychosis not due to a substance or known physiological condition is a billable ICD-10-CM diagnosis code (F29).Mental disorder, not otherwise specified is a billable ICD-10-CM diagnosis code (F99).
Includes
Psychosis NOS
Unspecified schizophrenia spectrum and other psychotic disorder
Mental illness NOS

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources