2026 ICD-10-CM Diagnosis Code F98.5Adult onset fluency disorder

ICD-10-CM Codes›F01–F99›F90-F98›F98

ICD-10-CM F98.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F98.5 is a billable ICD-10-CM diagnosis code for adult onset fluency disorder. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neurodevelopmental disorders.

Code Identity

ICD-10-CM Code
F98.5
Billable Status
Yes — Valid for Submission
Code Describes
Adult onset fluency disorder
Short Description
Adult onset fluency disorder
Same as the full description in the CMS dataset.
Parent Code
F98
Other behavioral and emotional disorders with onset usually occurring in childhood and adolescence

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF90-F98Behavioral and emotional disorders with onset usually occurring in childhood and adolescence
CategoryF98Other behavioral and emotional disorders with onset usually occurring in childhood and adolescence
This CodeF98.5Adult onset fluency disorder

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired stammering
  • Adult onset fluency disorder
  • Borderline stuttering
  • Covert stuttering
  • Developmental dysfluency
  • Developmental expressive language disorder
  • Disorder of fluency
  • Dysfluency
  • Idiopathic stammering
  • Neurogenic stammering
  • Normal non-fluency
  • Primary stuttering
  • Psychogenic stuttering
  • Psychogenic voice disorder
  • Secondary stuttering
  • Stuttering

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • childhood onset fluency disorder F80.81
  • dysphasia R47.02
  • fluency disorder in conditions classified elsewhere R47.82
  • fluency disorder (stuttering) following cerebrovascular disease (I69. with final characters -23)
  • tic disorders F95

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Disorder(of)
      • fluency
        • adult onset
    • Stuttering
      • adult onset

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MBD014
Neurodevelopmental disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Stuttering

    a disturbance in the normal fluency and time patterning of speech that is inappropriate for the individual's age. this disturbance is characterized by frequent repetitions or prolongations of sounds or syllables. various other types of speech dysfluencies may also be involved including interjections, broken words, audible or silent blocking, circumlocutions, words produced with an excess of physical tension, and monosyllabic whole word repetitions. stuttering may occur as a developmental condition in childhood or as an acquired disorder which may be associated with brain infarctions and other brain diseases. (from dsm-iv, 1994)

Patient EducationClinical

Stuttering

Stuttering is a speech disorder. It involves interruptions in the flow of speech. These interruptions are called disfluencies. They may involve:

The full article covers:

  • What is stuttering?
  • What causes stuttering?
  • Who is at risk for stuttering?
  • How is stuttering diagnosed?
  • What are the treatments for stuttering?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert F98.5 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
307.0 Adult onset flncy disord
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About F98.5Overview

Is F98.5 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report adult onset fluency disorder on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of F98.5?

Under the General Equivalence Mappings, adult onset fluency disorder converts to ICD-9-CM 307.0 (adult onset flncy disord). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.