2026 ICD-10-CM Diagnosis Code F34.0Cyclothymic disorder

ICD-10-CM Codes›F01–F99›F30-F39›F34

ICD-10-CM F34.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F34.0 is a billable ICD-10-CM diagnosis code for cyclothymic disorder. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as character trait finding of affective stability. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bipolar and related disorders.

Code Identity

ICD-10-CM Code
F34.0
Billable Status
Yes — Valid for Submission
Code Describes
Cyclothymic disorder
Short Description
Cyclothymic disorder
Same as the full description in the CMS dataset.
Parent Code
F34
Persistent mood [affective] disorders

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF30-F39Mood [affective] disorders
CategoryF34Persistent mood [affective] disorders
This CodeF34.0Cyclothymic disorder

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Character trait finding of affective stability
  • Cyclothymia
  • Cyclothymia in remission
  • Hypomanic personality trait
  • Trait affective instability

Tabular List NotesGuidance

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

Inclusion Terms

  • Affective personality disorder
  • Cycloid personality
  • Cyclothymia
  • Cyclothymic personality

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.

    • Cycloid personality
    • Cyclothymia
    • Cyclothymic personality
    • Disorder(of)
      • cyclothymic
    • Disorder(of)
      • mood
        • persistent
          • cyclothymia
    • Disorder(of)
      • personality
        • affective
    • Disorder(of)
      • personality
        • cyclothymic
    • Disorder(of)
      • personality
        • hyperthymic
    • Personality(disorder)
      • affective
    • Personality(disorder)
      • cycloid
    • Personality(disorder)
      • cyclothymic
    • Personality(disorder)
      • hyperthymic

Clinical ClassificationClinical

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

CCSR MBD003
Bipolar and related disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Cyclothymic Disorder

    an affective disorder characterized by periods of depression and hypomania. these may be separated by periods of normal mood.

Patient EducationClinical

Bipolar Disorder

Bipolar disorder is a mood disorder that can cause intense mood swings:

The full article covers:

  • What is bipolar disorder?
  • What are the types of bipolar disorder?
  • What causes bipolar disorder?
  • Who is at risk for bipolar disorder?
  • What are the symptoms of bipolar disorder?
  • How is bipolar disorder diagnosed?
  • What are the treatments for bipolar disorder?

Read the full article at MedlinePlus

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

Convert F34.0 to ICD-9-CMHistory

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

ICD-9-CM
301.10 Affectiv personality NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
301.13 Cyclothymic disorder
Approximate The match is approximate rather than exact.

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 F34.0Overview

Is F34.0 (Persistent mood [affective] disorders) a billable code?

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

What is the ICD-9 equivalent of F34.0?

Under the General Equivalence Mappings, cyclothymic disorder converts to ICD-9-CM 301.10 (affectiv personality NOS) and 301.13 (cyclothymic disorder). The mapping is approximate, so confirm the match fits the documentation.

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.