2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

F98.5 is a billable ICD-10-CM diagnosis code for adult onset fluency disorder. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 887. 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to F98.5: its own notes plus those printed at F98, block F90-F98, and Chapter 5. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Chapter 5 (F01-F99) Mental and behavioural disorders applies to 872 codes
  • disorders of psychological development

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • 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.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From F98 Other behavioral and emotional disorders with onset usually occurring in childhood and adolescence applies to 9 codes
  • breath-holding spells (R06.89)
  • gender identity disorder of childhood (F64.2)
  • Kleine-Levin syndrome (G47.13)
  • obsessive-compulsive disorder (F42.-)
  • sleep disorders not due to a substance or known physiological condition (F51.-)
From Chapter 5 (F01-F99) Mental and behavioural disorders applies to 872 codes
  • symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)

Notes

General instructions on how these codes are used.

From Block F90-F98 Behavioral and emotional disorders with onset usually occurring in childhood and adolescence applies to 33 codes
  • Codes within categories F90-F98 may be used regardless of the age of a patient. These disorders generally have onset within the childhood or adolescent years, but may continue throughout life or not be diagnosed until adulthood

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name F98.5, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming F98.5: they are not reported together with it, unless the two conditions are unrelated.

  • F80.81 Childhood onset fluency disorder
    adult onset fluency disorder (F98.5)
  • R47.82 Fluency disorder in conditions classified elsewhere
    adult onset fluency disorder (F98.5)

Notes 1

These notes mention F98.5.

  • Block F90-F98 Behavioral and emotional disorders with onset usually occurring in childhood and adolescence
    Codes within categories F90-F98 may be used regardless of the age of a patient. These disorders generally have onset within the childhood or adolescent years, but may continue throughout life or not be diagnosed until adulthood names F90-F98, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

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

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About F98.5Overview

What is the ICD-10 code for adult onset fluency disorder?

The ICD-10-CM code for adult onset fluency disorder is F98.5 (sometimes written as F985). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does F98.5 group to?

When adult onset fluency disorder is the principal diagnosis on an inpatient stay, it groups to MS-DRG 887 (other Mental Disorder Diagnoses), which carries a relative weight of 1.1154. Higher weights mean higher Medicare reimbursement.

Can F98.5 be reported with F80.81?

Not as a rule. The Excludes1 note on F98.5 lists "childhood onset fluency disorder (F80.81)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

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.