ICD-10 Code F98.5 – Adult onset fluency disorder (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F98.5 – Adult onset fluency disorder
What it is
F98.5 identifies adult onset fluency disorder, a speech disturbance that begins in adulthood and affects the flow and rhythm of speaking. You use it when documentation shows acquired stuttering or similar disfluency in an adult.
Clinical signs
Clinical features vary; refer to documentation. Common findings include interruptions in speech such as repetitions, prolongations, or blocks that interfere with fluent communication.
When to use this code
Use F98.5 when the record clearly documents adult onset fluency disorder or acquired stuttering. It fits outpatient, specialty, or inpatient notes that describe a new fluency problem beginning after childhood. Check documentation for onset and the clinician’s diagnosis.
Do not use for
Do not use this code for developmental stuttering that started in childhood or for nonspecific speech problems without a documented fluency disorder. Check documentation if the cause is another neurologic or psychiatric condition.
Coding tip
Verify that the onset is in adulthood and that the provider names a fluency disorder before assigning F98.5.